10 Printable Math Worksheets - Free Printable
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Step-by-step solution for: 10 Printable Math Worksheets
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Step-by-step solution for: 10 Printable Math Worksheets
To solve the problem of factoring the quadratic expressions, we will use various methods such as:
1. Factoring by Grouping
2. Difference of Squares
3. Perfect Square Trinomials
4. Trial and Error for General Quadratics
Let's go through each section step by step.
---
#### 1) \( 2x^2 + x - 1 \)
We look for two numbers that multiply to \( 2 \cdot (-1) = -2 \) and add to \( 1 \). These numbers are \( 2 \) and \( -1 \).
\[
2x^2 + x - 1 = 2x^2 + 2x - x - 1 = 2x(x + 1) - 1(x + 1) = (2x - 1)(x + 1)
\]
Answer: \( (2x - 1)(x + 1) \)
#### 2) \( 2x^2 + x - 3 \)
We look for two numbers that multiply to \( 2 \cdot (-3) = -6 \) and add to \( 1 \). These numbers are \( 3 \) and \( -2 \).
\[
2x^2 + x - 3 = 2x^2 + 3x - 2x - 3 = x(2x + 3) - 1(2x + 3) = (x - 1)(2x + 3)
\]
Answer: \( (x - 1)(2x + 3) \)
#### 3) \( 2x^2 + 9x - 5 \)
We look for two numbers that multiply to \( 2 \cdot (-5) = -10 \) and add to \( 9 \). These numbers are \( 10 \) and \( -1 \).
\[
2x^2 + 9x - 5 = 2x^2 + 10x - x - 5 = 2x(x + 5) - 1(x + 5) = (2x - 1)(x + 5)
\]
Answer: \( (2x - 1)(x + 5) \)
#### 4) \( 2x^2 - 3x - 2 \)
We look for two numbers that multiply to \( 2 \cdot (-2) = -4 \) and add to \( -3 \). These numbers are \( -4 \) and \( 1 \).
\[
2x^2 - 3x - 2 = 2x^2 - 4x + x - 2 = 2x(x - 2) + 1(x - 2) = (2x + 1)(x - 2)
\]
Answer: \( (2x + 1)(x - 2) \)
#### 5) \( 2x^2 - 13x - 24 \)
We look for two numbers that multiply to \( 2 \cdot (-24) = -48 \) and add to \( -13 \). These numbers are \( -16 \) and \( 3 \).
\[
2x^2 - 13x - 24 = 2x^2 - 16x + 3x - 24 = 2x(x - 8) + 3(x - 8) = (2x + 3)(x - 8)
\]
Answer: \( (2x + 3)(x - 8) \)
#### 6) \( 3x^2 - 14x - 5 \)
We look for two numbers that multiply to \( 3 \cdot (-5) = -15 \) and add to \( -14 \). These numbers are \( -15 \) and \( 1 \).
\[
3x^2 - 14x - 5 = 3x^2 - 15x + x - 5 = 3x(x - 5) + 1(x - 5) = (3x + 1)(x - 5)
\]
Answer: \( (3x + 1)(x - 5) \)
#### 7) \( 3x^2 - 8x - 11 \)
We look for two numbers that multiply to \( 3 \cdot (-11) = -33 \) and add to \( -8 \). These numbers are \( -11 \) and \( 3 \).
\[
3x^2 - 8x - 11 = 3x^2 - 11x + 3x - 11 = x(3x - 11) + 1(3x - 11) = (x + 1)(3x - 11)
\]
Answer: \( (x + 1)(3x - 11) \)
#### 8) \( 2x^2 - 14x + 12 \)
First, factor out the greatest common factor (GCF), which is \( 2 \):
\[
2x^2 - 14x + 12 = 2(x^2 - 7x + 6)
\]
Now, factor \( x^2 - 7x + 6 \). We look for two numbers that multiply to \( 6 \) and add to \( -7 \). These numbers are \( -6 \) and \( -1 \).
\[
x^2 - 7x + 6 = (x - 6)(x - 1)
\]
So,
\[
2x^2 - 14x + 12 = 2(x - 6)(x - 1)
\]
Answer: \( 2(x - 6)(x - 1) \)
#### 9) \( 3x^2 - 21x + 36 \)
First, factor out the GCF, which is \( 3 \):
\[
3x^2 - 21x + 36 = 3(x^2 - 7x + 12)
\]
Now, factor \( x^2 - 7x + 12 \). We look for two numbers that multiply to \( 12 \) and add to \( -7 \). These numbers are \( -4 \) and \( -3 \).
\[
x^2 - 7x + 12 = (x - 4)(x - 3)
\]
So,
\[
3x^2 - 21x + 36 = 3(x - 4)(x - 3)
\]
Answer: \( 3(x - 4)(x - 3) \)
#### 10) \( 5x^2 - 41x + 8 \)
We look for two numbers that multiply to \( 5 \cdot 8 = 40 \) and add to \( -41 \). These numbers are \( -40 \) and \( -1 \).
\[
5x^2 - 41x + 8 = 5x^2 - 40x - x + 8 = 5x(x - 8) - 1(x - 8) = (5x - 1)(x - 8)
\]
Answer: \( (5x - 1)(x - 8) \)
#### 11) \( 3x^2 - 2x - 21 \)
We look for two numbers that multiply to \( 3 \cdot (-21) = -63 \) and add to \( -2 \). These numbers are \( -9 \) and \( 7 \).
\[
3x^2 - 2x - 21 = 3x^2 - 9x + 7x - 21 = 3x(x - 3) + 7(x - 3) = (3x + 7)(x - 3)
\]
Answer: \( (3x + 7)(x - 3) \)
#### 12) \( 2x^2 + 2x - 12 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 2x - 12 = 2(x^2 + x - 6)
\]
Now, factor \( x^2 + x - 6 \). We look for two numbers that multiply to \( -6 \) and add to \( 1 \). These numbers are \( 3 \) and \( -2 \).
\[
x^2 + x - 6 = (x + 3)(x - 2)
\]
So,
\[
2x^2 + 2x - 12 = 2(x + 3)(x - 2)
\]
Answer: \( 2(x + 3)(x - 2) \)
#### 13) \( 2x^2 - 11x + 15 \)
We look for two numbers that multiply to \( 2 \cdot 15 = 30 \) and add to \( -11 \). These numbers are \( -6 \) and \( -5 \).
\[
2x^2 - 11x + 15 = 2x^2 - 6x - 5x + 15 = 2x(x - 3) - 5(x - 3) = (2x - 5)(x - 3)
\]
Answer: \( (2x - 5)(x - 3) \)
#### 14) \( 3x^2 - 34x - 24 \)
We look for two numbers that multiply to \( 3 \cdot (-24) = -72 \) and add to \( -34 \). These numbers are \( -36 \) and \( 2 \).
\[
3x^2 - 34x - 24 = 3x^2 - 36x + 2x - 24 = 3x(x - 12) + 2(x - 12) = (3x + 2)(x - 12)
\]
Answer: \( (3x + 2)(x - 12) \)
#### 15) \( 5x^2 - 27x + 10 \)
We look for two numbers that multiply to \( 5 \cdot 10 = 50 \) and add to \( -27 \). These numbers are \( -25 \) and \( -2 \).
\[
5x^2 - 27x + 10 = 5x^2 - 25x - 2x + 10 = 5x(x - 5) - 2(x - 5) = (5x - 2)(x - 5)
\]
Answer: \( (5x - 2)(x - 5) \)
---
#### 1) \( x^2 + 7x - 30 \)
We look for two numbers that multiply to \( -30 \) and add to \( 7 \). These numbers are \( 10 \) and \( -3 \).
\[
x^2 + 7x - 30 = (x + 10)(x - 3)
\]
Answer: \( (x + 10)(x - 3) \)
#### 2) \( x^2 + 9x + 20 \)
We look for two numbers that multiply to \( 20 \) and add to \( 9 \). These numbers are \( 5 \) and \( 4 \).
\[
x^2 + 9x + 20 = (x + 5)(x + 4)
\]
Answer: \( (x + 5)(x + 4) \)
#### 3) \( x^2 + 8x - 9 \)
We look for two numbers that multiply to \( -9 \) and add to \( 8 \). These numbers are \( 9 \) and \( -1 \).
\[
x^2 + 8x - 9 = (x + 9)(x - 1)
\]
Answer: \( (x + 9)(x - 1) \)
#### 4) \( x^2 - 18x + 80 \)
We look for two numbers that multiply to \( 80 \) and add to \( -18 \). These numbers are \( -10 \) and \( -8 \).
\[
x^2 - 18x + 80 = (x - 10)(x - 8)
\]
Answer: \( (x - 10)(x - 8) \)
#### 5) \( x^2 - 11x + 28 \)
We look for two numbers that multiply to \( 28 \) and add to \( -11 \). These numbers are \( -7 \) and \( -4 \).
\[
x^2 - 11x + 28 = (x - 7)(x - 4)
\]
Answer: \( (x - 7)(x - 4) \)
#### 6) \( x^2 + 6x - 72 \)
We look for two numbers that multiply to \( -72 \) and add to \( 6 \). These numbers are \( 12 \) and \( -6 \).
\[
x^2 + 6x - 72 = (x + 12)(x - 6)
\]
Answer: \( (x + 12)(x - 6) \)
#### 7) \( x^2 - 9x - 22 \)
We look for two numbers that multiply to \( -22 \) and add to \( -9 \). These numbers are \( -11 \) and \( 2 \).
\[
x^2 - 9x - 22 = (x - 11)(x + 2)
\]
Answer: \( (x - 11)(x + 2) \)
#### 8) \( x^2 - x - 12 \)
We look for two numbers that multiply to \( -12 \) and add to \( -1 \). These numbers are \( -4 \) and \( 3 \).
\[
x^2 - x - 12 = (x - 4)(x + 3)
\]
Answer: \( (x - 4)(x + 3) \)
#### 9) \( x^2 + 3x - 108 \)
We look for two numbers that multiply to \( -108 \) and add to \( 3 \). These numbers are \( 12 \) and \( -9 \).
\[
x^2 + 3x - 108 = (x + 12)(x - 9)
\]
Answer: \( (x + 12)(x - 9) \)
#### 10) \( x^2 - 17x + 72 \)
We look for two numbers that multiply to \( 72 \) and add to \( -17 \). These numbers are \( -8 \) and \( -9 \).
\[
x^2 - 17x + 72 = (x - 8)(x - 9)
\]
Answer: \( (x - 8)(x - 9) \)
#### 11) \( x^2 - x - 42 \)
We look for two numbers that multiply to \( -42 \) and add to \( -1 \). These numbers are \( -7 \) and \( 6 \).
\[
x^2 - x - 42 = (x - 7)(x + 6)
\]
Answer: \( (x - 7)(x + 6) \)
#### 12) \( x^2 - 15x + 56 \)
We look for two numbers that multiply to \( 56 \) and add to \( -15 \). These numbers are \( -7 \) and \( -8 \).
\[
x^2 - 15x + 56 = (x - 7)(x - 8)
\]
Answer: \( (x - 7)(x - 8) \)
---
#### 1) \( 2x^2 + 3x + 1 \)
We look for two numbers that multiply to \( 2 \cdot 1 = 2 \) and add to \( 3 \). These numbers are \( 2 \) and \( 1 \).
\[
2x^2 + 3x + 1 = 2x^2 + 2x + x + 1 = 2x(x + 1) + 1(x + 1) = (2x + 1)(x + 1)
\]
Answer: \( (2x + 1)(x + 1) \)
#### 2) \( 2x^2 + 5x + 2 \)
We look for two numbers that multiply to \( 2 \cdot 2 = 4 \) and add to \( 5 \). These numbers are \( 4 \) and \( 1 \).
\[
2x^2 + 5x + 2 = 2x^2 + 4x + x + 2 = 2x(x + 2) + 1(x + 2) = (2x + 1)(x + 2)
\]
Answer: \( (2x + 1)(x + 2) \)
#### 3) \( 2x^2 + 7x + 3 \)
We look for two numbers that multiply to \( 2 \cdot 3 = 6 \) and add to \( 7 \). These numbers are \( 6 \) and \( 1 \).
\[
2x^2 + 7x + 3 = 2x^2 + 6x + x + 3 = 2x(x + 3) + 1(x + 3) = (2x + 1)(x + 3)
\]
Answer: \( (2x + 1)(x + 3) \)
#### 4) \( 2x^2 + 7x + 5 \)
We look for two numbers that multiply to \( 2 \cdot 5 = 10 \) and add to \( 7 \). These numbers are \( 5 \) and \( 2 \).
\[
2x^2 + 7x + 5 = 2x^2 + 5x + 2x + 5 = x(2x + 5) + 1(2x + 5) = (x + 1)(2x + 5)
\]
Answer: \( (x + 1)(2x + 5) \)
#### 5) \( 2x^2 + 9x + 7 \)
We look for two numbers that multiply to \( 2 \cdot 7 = 14 \) and add to \( 9 \). These numbers are \( 7 \) and \( 2 \).
\[
2x^2 + 9x + 7 = 2x^2 + 7x + 2x + 7 = x(2x + 7) + 1(2x + 7) = (x + 1)(2x + 7)
\]
Answer: \( (x + 1)(2x + 7) \)
#### 6) \( 2x^2 + 5x + 3 \)
We look for two numbers that multiply to \( 2 \cdot 3 = 6 \) and add to \( 5 \). These numbers are \( 3 \) and \( 2 \).
\[
2x^2 + 5x + 3 = 2x^2 + 3x + 2x + 3 = x(2x + 3) + 1(2x + 3) = (x + 1)(2x + 3)
\]
Answer: \( (x + 1)(2x + 3) \)
#### 7) \( 2x^2 + 8x + 6 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 8x + 6 = 2(x^2 + 4x + 3)
\]
Now, factor \( x^2 + 4x + 3 \). We look for two numbers that multiply to \( 3 \) and add to \( 4 \). These numbers are \( 3 \) and \( 1 \).
\[
x^2 + 4x + 3 = (x + 3)(x + 1)
\]
So,
\[
2x^2 + 8x + 6 = 2(x + 3)(x + 1)
\]
Answer: \( 2(x + 3)(x + 1) \)
#### 8) \( 2x^2 + 9x + 10 \)
We look for two numbers that multiply to \( 2 \cdot 10 = 20 \) and add to \( 9 \). These numbers are \( 5 \) and \( 4 \).
\[
2x^2 + 9x + 10 = 2x^2 + 5x + 4x + 10 = x(2x + 5) + 2(2x + 5) = (x + 2)(2x + 5)
\]
Answer: \( (x + 2)(2x + 5) \)
#### 9) \( 2x^2 + 16x + 14 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 16x + 14 = 2(x^2 + 8x + 7)
\]
Now, factor \( x^2 + 8x + 7 \). We look for two numbers that multiply to \( 7 \) and add to \( 8 \). These numbers are \( 7 \) and \( 1 \).
\[
x^2 + 8x + 7 = (x + 7)(x + 1)
\]
So,
\[
2x^2 + 16x + 14 = 2(x + 7)(x + 1)
\]
Answer: \( 2(x + 7)(x + 1) \)
#### 10) \( 2x^2 + 16x + 24 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 16x + 24 = 2(x^2 + 8x + 12)
\]
Now, factor \( x^2 + 8x + 12 \). We look for two numbers that multiply to \( 12 \) and add to \( 8 \). These numbers are \( 6 \) and \( 2 \).
\[
x^2 + 8x + 12 = (x + 6)(x + 2)
\]
So,
\[
2x^2 + 16x + 24 = 2(x + 6)(x + 2)
\]
Answer: \( 2(x + 6)(x + 2) \)
#### 11) \( 2x^2 + 12x + 18 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 12x + 18 = 2(x^2 + 6x + 9)
\]
Now, factor \( x^2 + 6x + 9 \). This is a perfect square trinomial:
\[
x^2 + 6x + 9 = (x + 3)^2
\]
So,
\[
2x^2 + 12x + 18 = 2(x + 3)^2
\]
Answer: \( 2(x + 3)^2 \)
#### 12) \( 2x^2 + 14x + 20 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 14x + 20 = 2(x^2 + 7x + 10)
\]
Now, factor \( x^2 + 7x + 10 \). We look for two numbers that multiply to \( 10 \) and add to \( 7 \). These numbers are \( 5 \) and \( 2 \).
\[
x^2 + 7x + 10 = (x + 5)(x + 2)
\]
So,
\[
2x^2 + 14x + 20 = 2(x + 5)(x + 2)
\]
Answer: \( 2(x + 5)(x + 2) \)
#### 13) \( 2x^2 + 22x + 36 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 22x + 36 = 2(x^2 + 11x + 18)
\]
Now, factor \( x^2 + 11x + 18 \). We look for two numbers that multiply to \( 18 \) and add to \( 11 \). These numbers are \( 9 \) and \( 2 \).
\[
x^2 + 11x + 18 = (x + 9)(x + 2)
\]
So,
\[
2x^2 + 22x + 36 = 2(x + 9)(x + 2)
\]
Answer: \( 2(x + 9)(x + 2) \)
#### 14) \( 2x^2 + 28x + 48 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 28x + 48 = 2(x^2 + 14x + 24)
\]
Now, factor \( x^2 + 14x + 24 \). We look for two numbers that multiply to \( 24 \) and add to \( 14 \). These numbers are \( 12 \) and \( 2 \).
\[
x^2 + 14x + 24 = (x + 12)(x + 2)
\]
So,
\[
2x^2 + 28x + 48 = 2(x + 12)(x + 2)
\]
Answer: \( 2(x + 12)(x + 2) \)
#### 15) \( 2x^2 + 26x + 72 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 26x + 72 = 2(x^2 + 13x + 36)
\]
Now, factor \( x^2 + 13x + 36 \). We look for two numbers that multiply to \( 36 \) and add to \( 13 \). These numbers are \( 9 \) and \( 4 \).
\[
x^2 + 13x + 36 = (x + 9)(x + 4)
\]
So,
\[
2x^2 + 26x + 72 = 2(x + 9)(x + 4)
\]
Answer: \( 2(x + 9)(x + 4) \)
---
\[
\boxed{
\begin{array}{lll}
\text{Section A:} & \text{Section B:} & \text{Section C:} \\
1) (2x - 1)(x + 1) & 1) (x + 10)(x - 3) & 1) (2x + 1)(x + 1) \\
2) (x - 1)(2x + 3) & 2) (x + 5)(x + 4) & 2) (2x + 1)(x + 2) \\
3) (2x - 1)(x + 5) & 3) (x + 9)(x - 1) & 3) (2x + 1)(x + 3) \\
4) (2x + 1)(x - 2) & 4) (x - 10)(x - 8) & 4) (x + 1)(2x + 5) \\
5) (2x + 3)(x - 8) & 5) (x - 7)(x - 4) & 5) (x + 1)(2x + 7) \\
6) (3x + 1)(x - 5) & 6) (x + 12)(x - 6) & 6) (x + 1)(2x + 3) \\
7) (x + 1)(3x - 11) & 7) (x - 11)(x + 2) & 7) 2(x + 3)(x + 1) \\
8) 2(x - 6)(x - 1) & 8) (x - 4)(x + 3) & 8) (x + 2)(2x + 5) \\
9) 3(x - 4)(x - 3) & 9) (x + 12)(x - 9) & 9) 2(x + 7)(x + 1) \\
10) (5x - 1)(x - 8) & 10) (x - 8)(x - 9) & 10) 2(x + 6)(x + 2) \\
11) (3x + 7)(x - 3) & 11) (x - 7)(x + 6) & 11) 2(x + 3)^2 \\
12) 2(x + 3)(x - 2) & 12) (x - 7)(x - 8) & 12) 2(x + 5)(x + 2) \\
13) (2x - 5)(x - 3) & & 13) 2(x + 9)(x + 2) \\
14) (3x + 2)(x - 12) & & 14) 2(x + 12)(x + 2) \\
15) (5x - 2)(x - 5) & & 15) 2(x + 9)(x + 4) \\
\end{array}
}
\]
1. Factoring by Grouping
2. Difference of Squares
3. Perfect Square Trinomials
4. Trial and Error for General Quadratics
Let's go through each section step by step.
---
Section A: Factoring Quadratic Expressions
#### 1) \( 2x^2 + x - 1 \)
We look for two numbers that multiply to \( 2 \cdot (-1) = -2 \) and add to \( 1 \). These numbers are \( 2 \) and \( -1 \).
\[
2x^2 + x - 1 = 2x^2 + 2x - x - 1 = 2x(x + 1) - 1(x + 1) = (2x - 1)(x + 1)
\]
Answer: \( (2x - 1)(x + 1) \)
#### 2) \( 2x^2 + x - 3 \)
We look for two numbers that multiply to \( 2 \cdot (-3) = -6 \) and add to \( 1 \). These numbers are \( 3 \) and \( -2 \).
\[
2x^2 + x - 3 = 2x^2 + 3x - 2x - 3 = x(2x + 3) - 1(2x + 3) = (x - 1)(2x + 3)
\]
Answer: \( (x - 1)(2x + 3) \)
#### 3) \( 2x^2 + 9x - 5 \)
We look for two numbers that multiply to \( 2 \cdot (-5) = -10 \) and add to \( 9 \). These numbers are \( 10 \) and \( -1 \).
\[
2x^2 + 9x - 5 = 2x^2 + 10x - x - 5 = 2x(x + 5) - 1(x + 5) = (2x - 1)(x + 5)
\]
Answer: \( (2x - 1)(x + 5) \)
#### 4) \( 2x^2 - 3x - 2 \)
We look for two numbers that multiply to \( 2 \cdot (-2) = -4 \) and add to \( -3 \). These numbers are \( -4 \) and \( 1 \).
\[
2x^2 - 3x - 2 = 2x^2 - 4x + x - 2 = 2x(x - 2) + 1(x - 2) = (2x + 1)(x - 2)
\]
Answer: \( (2x + 1)(x - 2) \)
#### 5) \( 2x^2 - 13x - 24 \)
We look for two numbers that multiply to \( 2 \cdot (-24) = -48 \) and add to \( -13 \). These numbers are \( -16 \) and \( 3 \).
\[
2x^2 - 13x - 24 = 2x^2 - 16x + 3x - 24 = 2x(x - 8) + 3(x - 8) = (2x + 3)(x - 8)
\]
Answer: \( (2x + 3)(x - 8) \)
#### 6) \( 3x^2 - 14x - 5 \)
We look for two numbers that multiply to \( 3 \cdot (-5) = -15 \) and add to \( -14 \). These numbers are \( -15 \) and \( 1 \).
\[
3x^2 - 14x - 5 = 3x^2 - 15x + x - 5 = 3x(x - 5) + 1(x - 5) = (3x + 1)(x - 5)
\]
Answer: \( (3x + 1)(x - 5) \)
#### 7) \( 3x^2 - 8x - 11 \)
We look for two numbers that multiply to \( 3 \cdot (-11) = -33 \) and add to \( -8 \). These numbers are \( -11 \) and \( 3 \).
\[
3x^2 - 8x - 11 = 3x^2 - 11x + 3x - 11 = x(3x - 11) + 1(3x - 11) = (x + 1)(3x - 11)
\]
Answer: \( (x + 1)(3x - 11) \)
#### 8) \( 2x^2 - 14x + 12 \)
First, factor out the greatest common factor (GCF), which is \( 2 \):
\[
2x^2 - 14x + 12 = 2(x^2 - 7x + 6)
\]
Now, factor \( x^2 - 7x + 6 \). We look for two numbers that multiply to \( 6 \) and add to \( -7 \). These numbers are \( -6 \) and \( -1 \).
\[
x^2 - 7x + 6 = (x - 6)(x - 1)
\]
So,
\[
2x^2 - 14x + 12 = 2(x - 6)(x - 1)
\]
Answer: \( 2(x - 6)(x - 1) \)
#### 9) \( 3x^2 - 21x + 36 \)
First, factor out the GCF, which is \( 3 \):
\[
3x^2 - 21x + 36 = 3(x^2 - 7x + 12)
\]
Now, factor \( x^2 - 7x + 12 \). We look for two numbers that multiply to \( 12 \) and add to \( -7 \). These numbers are \( -4 \) and \( -3 \).
\[
x^2 - 7x + 12 = (x - 4)(x - 3)
\]
So,
\[
3x^2 - 21x + 36 = 3(x - 4)(x - 3)
\]
Answer: \( 3(x - 4)(x - 3) \)
#### 10) \( 5x^2 - 41x + 8 \)
We look for two numbers that multiply to \( 5 \cdot 8 = 40 \) and add to \( -41 \). These numbers are \( -40 \) and \( -1 \).
\[
5x^2 - 41x + 8 = 5x^2 - 40x - x + 8 = 5x(x - 8) - 1(x - 8) = (5x - 1)(x - 8)
\]
Answer: \( (5x - 1)(x - 8) \)
#### 11) \( 3x^2 - 2x - 21 \)
We look for two numbers that multiply to \( 3 \cdot (-21) = -63 \) and add to \( -2 \). These numbers are \( -9 \) and \( 7 \).
\[
3x^2 - 2x - 21 = 3x^2 - 9x + 7x - 21 = 3x(x - 3) + 7(x - 3) = (3x + 7)(x - 3)
\]
Answer: \( (3x + 7)(x - 3) \)
#### 12) \( 2x^2 + 2x - 12 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 2x - 12 = 2(x^2 + x - 6)
\]
Now, factor \( x^2 + x - 6 \). We look for two numbers that multiply to \( -6 \) and add to \( 1 \). These numbers are \( 3 \) and \( -2 \).
\[
x^2 + x - 6 = (x + 3)(x - 2)
\]
So,
\[
2x^2 + 2x - 12 = 2(x + 3)(x - 2)
\]
Answer: \( 2(x + 3)(x - 2) \)
#### 13) \( 2x^2 - 11x + 15 \)
We look for two numbers that multiply to \( 2 \cdot 15 = 30 \) and add to \( -11 \). These numbers are \( -6 \) and \( -5 \).
\[
2x^2 - 11x + 15 = 2x^2 - 6x - 5x + 15 = 2x(x - 3) - 5(x - 3) = (2x - 5)(x - 3)
\]
Answer: \( (2x - 5)(x - 3) \)
#### 14) \( 3x^2 - 34x - 24 \)
We look for two numbers that multiply to \( 3 \cdot (-24) = -72 \) and add to \( -34 \). These numbers are \( -36 \) and \( 2 \).
\[
3x^2 - 34x - 24 = 3x^2 - 36x + 2x - 24 = 3x(x - 12) + 2(x - 12) = (3x + 2)(x - 12)
\]
Answer: \( (3x + 2)(x - 12) \)
#### 15) \( 5x^2 - 27x + 10 \)
We look for two numbers that multiply to \( 5 \cdot 10 = 50 \) and add to \( -27 \). These numbers are \( -25 \) and \( -2 \).
\[
5x^2 - 27x + 10 = 5x^2 - 25x - 2x + 10 = 5x(x - 5) - 2(x - 5) = (5x - 2)(x - 5)
\]
Answer: \( (5x - 2)(x - 5) \)
---
Section B: Factoring Quadratic Expressions
#### 1) \( x^2 + 7x - 30 \)
We look for two numbers that multiply to \( -30 \) and add to \( 7 \). These numbers are \( 10 \) and \( -3 \).
\[
x^2 + 7x - 30 = (x + 10)(x - 3)
\]
Answer: \( (x + 10)(x - 3) \)
#### 2) \( x^2 + 9x + 20 \)
We look for two numbers that multiply to \( 20 \) and add to \( 9 \). These numbers are \( 5 \) and \( 4 \).
\[
x^2 + 9x + 20 = (x + 5)(x + 4)
\]
Answer: \( (x + 5)(x + 4) \)
#### 3) \( x^2 + 8x - 9 \)
We look for two numbers that multiply to \( -9 \) and add to \( 8 \). These numbers are \( 9 \) and \( -1 \).
\[
x^2 + 8x - 9 = (x + 9)(x - 1)
\]
Answer: \( (x + 9)(x - 1) \)
#### 4) \( x^2 - 18x + 80 \)
We look for two numbers that multiply to \( 80 \) and add to \( -18 \). These numbers are \( -10 \) and \( -8 \).
\[
x^2 - 18x + 80 = (x - 10)(x - 8)
\]
Answer: \( (x - 10)(x - 8) \)
#### 5) \( x^2 - 11x + 28 \)
We look for two numbers that multiply to \( 28 \) and add to \( -11 \). These numbers are \( -7 \) and \( -4 \).
\[
x^2 - 11x + 28 = (x - 7)(x - 4)
\]
Answer: \( (x - 7)(x - 4) \)
#### 6) \( x^2 + 6x - 72 \)
We look for two numbers that multiply to \( -72 \) and add to \( 6 \). These numbers are \( 12 \) and \( -6 \).
\[
x^2 + 6x - 72 = (x + 12)(x - 6)
\]
Answer: \( (x + 12)(x - 6) \)
#### 7) \( x^2 - 9x - 22 \)
We look for two numbers that multiply to \( -22 \) and add to \( -9 \). These numbers are \( -11 \) and \( 2 \).
\[
x^2 - 9x - 22 = (x - 11)(x + 2)
\]
Answer: \( (x - 11)(x + 2) \)
#### 8) \( x^2 - x - 12 \)
We look for two numbers that multiply to \( -12 \) and add to \( -1 \). These numbers are \( -4 \) and \( 3 \).
\[
x^2 - x - 12 = (x - 4)(x + 3)
\]
Answer: \( (x - 4)(x + 3) \)
#### 9) \( x^2 + 3x - 108 \)
We look for two numbers that multiply to \( -108 \) and add to \( 3 \). These numbers are \( 12 \) and \( -9 \).
\[
x^2 + 3x - 108 = (x + 12)(x - 9)
\]
Answer: \( (x + 12)(x - 9) \)
#### 10) \( x^2 - 17x + 72 \)
We look for two numbers that multiply to \( 72 \) and add to \( -17 \). These numbers are \( -8 \) and \( -9 \).
\[
x^2 - 17x + 72 = (x - 8)(x - 9)
\]
Answer: \( (x - 8)(x - 9) \)
#### 11) \( x^2 - x - 42 \)
We look for two numbers that multiply to \( -42 \) and add to \( -1 \). These numbers are \( -7 \) and \( 6 \).
\[
x^2 - x - 42 = (x - 7)(x + 6)
\]
Answer: \( (x - 7)(x + 6) \)
#### 12) \( x^2 - 15x + 56 \)
We look for two numbers that multiply to \( 56 \) and add to \( -15 \). These numbers are \( -7 \) and \( -8 \).
\[
x^2 - 15x + 56 = (x - 7)(x - 8)
\]
Answer: \( (x - 7)(x - 8) \)
---
Section C: Factoring Quadratic Expressions
#### 1) \( 2x^2 + 3x + 1 \)
We look for two numbers that multiply to \( 2 \cdot 1 = 2 \) and add to \( 3 \). These numbers are \( 2 \) and \( 1 \).
\[
2x^2 + 3x + 1 = 2x^2 + 2x + x + 1 = 2x(x + 1) + 1(x + 1) = (2x + 1)(x + 1)
\]
Answer: \( (2x + 1)(x + 1) \)
#### 2) \( 2x^2 + 5x + 2 \)
We look for two numbers that multiply to \( 2 \cdot 2 = 4 \) and add to \( 5 \). These numbers are \( 4 \) and \( 1 \).
\[
2x^2 + 5x + 2 = 2x^2 + 4x + x + 2 = 2x(x + 2) + 1(x + 2) = (2x + 1)(x + 2)
\]
Answer: \( (2x + 1)(x + 2) \)
#### 3) \( 2x^2 + 7x + 3 \)
We look for two numbers that multiply to \( 2 \cdot 3 = 6 \) and add to \( 7 \). These numbers are \( 6 \) and \( 1 \).
\[
2x^2 + 7x + 3 = 2x^2 + 6x + x + 3 = 2x(x + 3) + 1(x + 3) = (2x + 1)(x + 3)
\]
Answer: \( (2x + 1)(x + 3) \)
#### 4) \( 2x^2 + 7x + 5 \)
We look for two numbers that multiply to \( 2 \cdot 5 = 10 \) and add to \( 7 \). These numbers are \( 5 \) and \( 2 \).
\[
2x^2 + 7x + 5 = 2x^2 + 5x + 2x + 5 = x(2x + 5) + 1(2x + 5) = (x + 1)(2x + 5)
\]
Answer: \( (x + 1)(2x + 5) \)
#### 5) \( 2x^2 + 9x + 7 \)
We look for two numbers that multiply to \( 2 \cdot 7 = 14 \) and add to \( 9 \). These numbers are \( 7 \) and \( 2 \).
\[
2x^2 + 9x + 7 = 2x^2 + 7x + 2x + 7 = x(2x + 7) + 1(2x + 7) = (x + 1)(2x + 7)
\]
Answer: \( (x + 1)(2x + 7) \)
#### 6) \( 2x^2 + 5x + 3 \)
We look for two numbers that multiply to \( 2 \cdot 3 = 6 \) and add to \( 5 \). These numbers are \( 3 \) and \( 2 \).
\[
2x^2 + 5x + 3 = 2x^2 + 3x + 2x + 3 = x(2x + 3) + 1(2x + 3) = (x + 1)(2x + 3)
\]
Answer: \( (x + 1)(2x + 3) \)
#### 7) \( 2x^2 + 8x + 6 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 8x + 6 = 2(x^2 + 4x + 3)
\]
Now, factor \( x^2 + 4x + 3 \). We look for two numbers that multiply to \( 3 \) and add to \( 4 \). These numbers are \( 3 \) and \( 1 \).
\[
x^2 + 4x + 3 = (x + 3)(x + 1)
\]
So,
\[
2x^2 + 8x + 6 = 2(x + 3)(x + 1)
\]
Answer: \( 2(x + 3)(x + 1) \)
#### 8) \( 2x^2 + 9x + 10 \)
We look for two numbers that multiply to \( 2 \cdot 10 = 20 \) and add to \( 9 \). These numbers are \( 5 \) and \( 4 \).
\[
2x^2 + 9x + 10 = 2x^2 + 5x + 4x + 10 = x(2x + 5) + 2(2x + 5) = (x + 2)(2x + 5)
\]
Answer: \( (x + 2)(2x + 5) \)
#### 9) \( 2x^2 + 16x + 14 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 16x + 14 = 2(x^2 + 8x + 7)
\]
Now, factor \( x^2 + 8x + 7 \). We look for two numbers that multiply to \( 7 \) and add to \( 8 \). These numbers are \( 7 \) and \( 1 \).
\[
x^2 + 8x + 7 = (x + 7)(x + 1)
\]
So,
\[
2x^2 + 16x + 14 = 2(x + 7)(x + 1)
\]
Answer: \( 2(x + 7)(x + 1) \)
#### 10) \( 2x^2 + 16x + 24 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 16x + 24 = 2(x^2 + 8x + 12)
\]
Now, factor \( x^2 + 8x + 12 \). We look for two numbers that multiply to \( 12 \) and add to \( 8 \). These numbers are \( 6 \) and \( 2 \).
\[
x^2 + 8x + 12 = (x + 6)(x + 2)
\]
So,
\[
2x^2 + 16x + 24 = 2(x + 6)(x + 2)
\]
Answer: \( 2(x + 6)(x + 2) \)
#### 11) \( 2x^2 + 12x + 18 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 12x + 18 = 2(x^2 + 6x + 9)
\]
Now, factor \( x^2 + 6x + 9 \). This is a perfect square trinomial:
\[
x^2 + 6x + 9 = (x + 3)^2
\]
So,
\[
2x^2 + 12x + 18 = 2(x + 3)^2
\]
Answer: \( 2(x + 3)^2 \)
#### 12) \( 2x^2 + 14x + 20 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 14x + 20 = 2(x^2 + 7x + 10)
\]
Now, factor \( x^2 + 7x + 10 \). We look for two numbers that multiply to \( 10 \) and add to \( 7 \). These numbers are \( 5 \) and \( 2 \).
\[
x^2 + 7x + 10 = (x + 5)(x + 2)
\]
So,
\[
2x^2 + 14x + 20 = 2(x + 5)(x + 2)
\]
Answer: \( 2(x + 5)(x + 2) \)
#### 13) \( 2x^2 + 22x + 36 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 22x + 36 = 2(x^2 + 11x + 18)
\]
Now, factor \( x^2 + 11x + 18 \). We look for two numbers that multiply to \( 18 \) and add to \( 11 \). These numbers are \( 9 \) and \( 2 \).
\[
x^2 + 11x + 18 = (x + 9)(x + 2)
\]
So,
\[
2x^2 + 22x + 36 = 2(x + 9)(x + 2)
\]
Answer: \( 2(x + 9)(x + 2) \)
#### 14) \( 2x^2 + 28x + 48 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 28x + 48 = 2(x^2 + 14x + 24)
\]
Now, factor \( x^2 + 14x + 24 \). We look for two numbers that multiply to \( 24 \) and add to \( 14 \). These numbers are \( 12 \) and \( 2 \).
\[
x^2 + 14x + 24 = (x + 12)(x + 2)
\]
So,
\[
2x^2 + 28x + 48 = 2(x + 12)(x + 2)
\]
Answer: \( 2(x + 12)(x + 2) \)
#### 15) \( 2x^2 + 26x + 72 \)
First, factor out the GCF, which is \( 2 \):
\[
2x^2 + 26x + 72 = 2(x^2 + 13x + 36)
\]
Now, factor \( x^2 + 13x + 36 \). We look for two numbers that multiply to \( 36 \) and add to \( 13 \). These numbers are \( 9 \) and \( 4 \).
\[
x^2 + 13x + 36 = (x + 9)(x + 4)
\]
So,
\[
2x^2 + 26x + 72 = 2(x + 9)(x + 4)
\]
Answer: \( 2(x + 9)(x + 4) \)
---
Final Answer:
\[
\boxed{
\begin{array}{lll}
\text{Section A:} & \text{Section B:} & \text{Section C:} \\
1) (2x - 1)(x + 1) & 1) (x + 10)(x - 3) & 1) (2x + 1)(x + 1) \\
2) (x - 1)(2x + 3) & 2) (x + 5)(x + 4) & 2) (2x + 1)(x + 2) \\
3) (2x - 1)(x + 5) & 3) (x + 9)(x - 1) & 3) (2x + 1)(x + 3) \\
4) (2x + 1)(x - 2) & 4) (x - 10)(x - 8) & 4) (x + 1)(2x + 5) \\
5) (2x + 3)(x - 8) & 5) (x - 7)(x - 4) & 5) (x + 1)(2x + 7) \\
6) (3x + 1)(x - 5) & 6) (x + 12)(x - 6) & 6) (x + 1)(2x + 3) \\
7) (x + 1)(3x - 11) & 7) (x - 11)(x + 2) & 7) 2(x + 3)(x + 1) \\
8) 2(x - 6)(x - 1) & 8) (x - 4)(x + 3) & 8) (x + 2)(2x + 5) \\
9) 3(x - 4)(x - 3) & 9) (x + 12)(x - 9) & 9) 2(x + 7)(x + 1) \\
10) (5x - 1)(x - 8) & 10) (x - 8)(x - 9) & 10) 2(x + 6)(x + 2) \\
11) (3x + 7)(x - 3) & 11) (x - 7)(x + 6) & 11) 2(x + 3)^2 \\
12) 2(x + 3)(x - 2) & 12) (x - 7)(x - 8) & 12) 2(x + 5)(x + 2) \\
13) (2x - 5)(x - 3) & & 13) 2(x + 9)(x + 2) \\
14) (3x + 2)(x - 12) & & 14) 2(x + 12)(x + 2) \\
15) (5x - 2)(x - 5) & & 15) 2(x + 9)(x + 4) \\
\end{array}
}
\]
Parent Tip: Review the logic above to help your child master the concept of math 9th grade worksheet.