Simplify the given algebraic expressions in Gamma Exercise 1.
Gamma Exercise 1 worksheet with six algebraic expressions to simplify, including fractions with variables.
PNG
1920×1080
126.4 KB
Free · Personal Use
Quality Assured by Worksheets Library Team
Reviewed for educational accuracy and age-appropriateness
ID: #380256
⭐
Show Answer Key & Explanations
Step-by-step solution for: A4g - Adding and subtracting algebraic fractions - BossMaths.com
▼
Show Answer Key & Explanations
Step-by-step solution for: A4g - Adding and subtracting algebraic fractions - BossMaths.com
Let's solve each of these algebraic expressions step by step, simplifying them as much as possible. We'll work through each one carefully.
---
$$
\frac{x+4}{x-3} - \frac{x-7}{x+1}
$$
We need a common denominator: $(x - 3)(x + 1)$
Rewrite both fractions:
$$
= \frac{(x+4)(x+1)}{(x-3)(x+1)} - \frac{(x-7)(x-3)}{(x+1)(x-3)}
$$
Now subtract the numerators:
$$
= \frac{(x+4)(x+1) - (x-7)(x-3)}{(x-3)(x+1)}
$$
Expand both:
- $(x+4)(x+1) = x^2 + x + 4x + 4 = x^2 + 5x + 4$
- $(x-7)(x-3) = x^2 - 3x - 7x + 21 = x^2 - 10x + 21$
Subtract:
$$
x^2 + 5x + 4 - (x^2 - 10x + 21) = x^2 + 5x + 4 - x^2 + 10x - 21 = 15x - 17
$$
So the expression becomes:
$$
\boxed{\frac{15x - 17}{(x-3)(x+1)}}
$$
✔ Answer: $\boxed{\frac{15x - 17}{(x-3)(x+1)}}$
---
$$
\frac{2w+4}{w-5} - \frac{w-7}{3w+1}
$$
Factor numerator of first fraction:
$$
= \frac{2(w+2)}{w-5} - \frac{w-7}{3w+1}
$$
Common denominator: $(w - 5)(3w + 1)$
$$
= \frac{2(w+2)(3w+1) - (w-7)(w-5)}{(w-5)(3w+1)}
$$
Expand numerator:
First term: $2(w+2)(3w+1)$
- $(w+2)(3w+1) = 3w^2 + w + 6w + 2 = 3w^2 + 7w + 2$
- Multiply by 2: $6w^2 + 14w + 4$
Second term: $(w-7)(w-5) = w^2 - 5w - 7w + 35 = w^2 - 12w + 35$
Now subtract:
$$
6w^2 + 14w + 4 - (w^2 - 12w + 35) = 6w^2 + 14w + 4 - w^2 + 12w - 35 = 5w^2 + 26w - 31
$$
So:
$$
\boxed{\frac{5w^2 + 26w - 31}{(w-5)(3w+1)}}
$$
✔ Answer: $\boxed{\frac{5w^2 + 26w - 31}{(w-5)(3w+1)}}$
---
$$
\frac{3(q+4)}{5-q} - \frac{2(q-7)}{q+4}
$$
Note: $5 - q = -(q - 5)$, but let’s keep it as is for now.
We can write $5 - q = -(q - 5)$, but perhaps better to just use common denominator.
Denominators: $5 - q$ and $q + 4$
Common denominator: $(5 - q)(q + 4)$
But note: $5 - q = -(q - 5)$, so we can write:
$$
= \frac{3(q+4)}{5-q} - \frac{2(q-7)}{q+4}
= \frac{3(q+4)}{-(q-5)} - \frac{2(q-7)}{q+4}
= -\frac{3(q+4)}{q-5} - \frac{2(q-7)}{q+4}
$$
But maybe easier to proceed directly.
Use common denominator: $(5 - q)(q + 4)$
So:
$$
= \frac{3(q+4)(q+4) - 2(q-7)(5-q)}{(5-q)(q+4)}
$$
Wait — careful: first term is $\frac{3(q+4)}{5-q}$, so numerator is $3(q+4)$ times $(q+4)$? No!
Actually:
$$
\frac{A}{B} - \frac{C}{D} = \frac{A \cdot D - C \cdot B}{B \cdot D}
$$
So:
$$
= \frac{3(q+4)(q+4) - 2(q-7)(5-q)}{(5-q)(q+4)}
$$
Wait — no! First fraction: numerator is $3(q+4)$, denominator $5 - q$
Second: numerator $2(q-7)$, denominator $q+4$
So:
$$
= \frac{3(q+4) \cdot (q+4) - 2(q-7) \cdot (5 - q)}{(5 - q)(q + 4)}
$$
Yes:
$$
= \frac{3(q+4)^2 - 2(q-7)(5 - q)}{(5 - q)(q + 4)}
$$
Now expand:
- $(q+4)^2 = q^2 + 8q + 16$, so $3(q^2 + 8q + 16) = 3q^2 + 24q + 48$
- $(q-7)(5 - q) = q(5 - q) - 7(5 - q) = 5q - q^2 - 35 + 7q = -q^2 + 12q - 35$
Then multiply by 2: $-2q^2 + 24q - 70$
Now subtract: $3q^2 + 24q + 48 - (-2q^2 + 24q - 70)$
Wait — in the formula: it's $A D - C B$, so:
$$
3(q+4)^2 - 2(q-7)(5 - q)
= (3q^2 + 24q + 48) - (-2q^2 + 24q - 70)
= 3q^2 + 24q + 48 + 2q^2 - 24q + 70
= 5q^2 + 118
$$
So numerator: $5q^2 + 118$
Denominator: $(5 - q)(q + 4)$
So:
$$
\boxed{\frac{5q^2 + 118}{(5 - q)(q + 4)}}
$$
Alternatively, write $5 - q = -(q - 5)$, so:
$$
= \frac{5q^2 + 118}{-(q - 5)(q + 4)} = -\frac{5q^2 + 118}{(q - 5)(q + 4)}
$$
But unless factoring helps, leave as:
✔ Answer: $\boxed{\frac{5q^2 + 118}{(5 - q)(q + 4)}}$
---
$$
\frac{2(1 - x)}{x + 2} + \frac{2x}{x + 7}
$$
Simplify first: $2(1 - x) = 2 - 2x$, so:
$$
= \frac{2 - 2x}{x + 2} + \frac{2x}{x + 7}
$$
Factor numerator: $2(1 - x)$
But $1 - x = -(x - 1)$, so:
$$
= \frac{-2(x - 1)}{x + 2} + \frac{2x}{x + 7}
$$
Now common denominator: $(x + 2)(x + 7)$
$$
= \frac{-2(x - 1)(x + 7) + 2x(x + 2)}{(x + 2)(x + 7)}
$$
Expand numerator:
First: $-2(x - 1)(x + 7)$
- $(x - 1)(x + 7) = x^2 + 7x - x - 7 = x^2 + 6x - 7$
- Multiply by -2: $-2x^2 - 12x + 14$
Second: $2x(x + 2) = 2x^2 + 4x$
Add together:
$$
(-2x^2 - 12x + 14) + (2x^2 + 4x) = (-2x^2 + 2x^2) + (-12x + 4x) + 14 = -8x + 14
$$
So:
$$
\boxed{\frac{-8x + 14}{(x + 2)(x + 7)}}
$$
Factor numerator: $-2(4x - 7)$ or $2(-4x + 7)$
So:
$$
= \frac{2(7 - 4x)}{(x + 2)(x + 7)}
$$
✔ Answer: $\boxed{\frac{2(7 - 4x)}{(x + 2)(x + 7)}}$
---
$$
\frac{5 - x}{y + 3} + \frac{2y}{x}
$$
Different variables — no common factors.
Common denominator: $x(y + 3)$
$$
= \frac{(5 - x)x + 2y(y + 3)}{x(y + 3)}
$$
Expand numerator:
- $(5 - x)x = 5x - x^2$
- $2y(y + 3) = 2y^2 + 6y$
Add: $5x - x^2 + 2y^2 + 6y$
Arrange: $-x^2 + 5x + 2y^2 + 6y$
So:
$$
\boxed{\frac{-x^2 + 5x + 2y^2 + 6y}{x(y + 3)}}
$$
No further simplification possible.
✔ Answer: $\boxed{\frac{-x^2 + 5x + 2y^2 + 6y}{x(y + 3)}}$
---
$$
\frac{3(a+4)}{b+2} - \frac{2(a-7)}{b+4}
$$
Different denominators: $b+2$, $b+4$
Common denominator: $(b+2)(b+4)$
$$
= \frac{3(a+4)(b+4) - 2(a-7)(b+2)}{(b+2)(b+4)}
$$
Expand numerator:
First: $3(a+4)(b+4)$
- $(a+4)(b+4) = ab + 4a + 4b + 16$
- Multiply by 3: $3ab + 12a + 12b + 48$
Second: $2(a-7)(b+2)$
- $(a-7)(b+2) = ab + 2a - 7b - 14$
- Multiply by 2: $2ab + 4a - 14b - 28$
Now subtract:
$$
(3ab + 12a + 12b + 48) - (2ab + 4a - 14b - 28)
= 3ab - 2ab + 12a - 4a + 12b + 14b + 48 + 28
= ab + 8a + 26b + 76
$$
So:
$$
\boxed{\frac{ab + 8a + 26b + 76}{(b+2)(b+4)}}
$$
Can this be factored? Let's see:
Numerator: $ab + 8a + 26b + 76$
Try grouping:
= $a(b + 8) + 2(13b + 38)$ — doesn't help.
Or: $a(b + 8) + 26b + 76$
Not factorable easily.
So leave as is.
✔ Answer: $\boxed{\frac{ab + 8a + 26b + 76}{(b+2)(b+4)}}$
---
1) $\boxed{\frac{15x - 17}{(x-3)(x+1)}}$
2) $\boxed{\frac{5w^2 + 26w - 31}{(w-5)(3w+1)}}$
3) $\boxed{\frac{5q^2 + 118}{(5 - q)(q + 4)}}$
4) $\boxed{\frac{2(7 - 4x)}{(x + 2)(x + 7)}}$
5) $\boxed{\frac{-x^2 + 5x + 2y^2 + 6y}{x(y + 3)}}$
6) $\boxed{\frac{ab + 8a + 26b + 76}{(b+2)(b+4)}}$
Let me know if you'd like any of them checked further!
---
1)
$$
\frac{x+4}{x-3} - \frac{x-7}{x+1}
$$
We need a common denominator: $(x - 3)(x + 1)$
Rewrite both fractions:
$$
= \frac{(x+4)(x+1)}{(x-3)(x+1)} - \frac{(x-7)(x-3)}{(x+1)(x-3)}
$$
Now subtract the numerators:
$$
= \frac{(x+4)(x+1) - (x-7)(x-3)}{(x-3)(x+1)}
$$
Expand both:
- $(x+4)(x+1) = x^2 + x + 4x + 4 = x^2 + 5x + 4$
- $(x-7)(x-3) = x^2 - 3x - 7x + 21 = x^2 - 10x + 21$
Subtract:
$$
x^2 + 5x + 4 - (x^2 - 10x + 21) = x^2 + 5x + 4 - x^2 + 10x - 21 = 15x - 17
$$
So the expression becomes:
$$
\boxed{\frac{15x - 17}{(x-3)(x+1)}}
$$
✔ Answer: $\boxed{\frac{15x - 17}{(x-3)(x+1)}}$
---
2)
$$
\frac{2w+4}{w-5} - \frac{w-7}{3w+1}
$$
Factor numerator of first fraction:
$$
= \frac{2(w+2)}{w-5} - \frac{w-7}{3w+1}
$$
Common denominator: $(w - 5)(3w + 1)$
$$
= \frac{2(w+2)(3w+1) - (w-7)(w-5)}{(w-5)(3w+1)}
$$
Expand numerator:
First term: $2(w+2)(3w+1)$
- $(w+2)(3w+1) = 3w^2 + w + 6w + 2 = 3w^2 + 7w + 2$
- Multiply by 2: $6w^2 + 14w + 4$
Second term: $(w-7)(w-5) = w^2 - 5w - 7w + 35 = w^2 - 12w + 35$
Now subtract:
$$
6w^2 + 14w + 4 - (w^2 - 12w + 35) = 6w^2 + 14w + 4 - w^2 + 12w - 35 = 5w^2 + 26w - 31
$$
So:
$$
\boxed{\frac{5w^2 + 26w - 31}{(w-5)(3w+1)}}
$$
✔ Answer: $\boxed{\frac{5w^2 + 26w - 31}{(w-5)(3w+1)}}$
---
3)
$$
\frac{3(q+4)}{5-q} - \frac{2(q-7)}{q+4}
$$
Note: $5 - q = -(q - 5)$, but let’s keep it as is for now.
We can write $5 - q = -(q - 5)$, but perhaps better to just use common denominator.
Denominators: $5 - q$ and $q + 4$
Common denominator: $(5 - q)(q + 4)$
But note: $5 - q = -(q - 5)$, so we can write:
$$
= \frac{3(q+4)}{5-q} - \frac{2(q-7)}{q+4}
= \frac{3(q+4)}{-(q-5)} - \frac{2(q-7)}{q+4}
= -\frac{3(q+4)}{q-5} - \frac{2(q-7)}{q+4}
$$
But maybe easier to proceed directly.
Use common denominator: $(5 - q)(q + 4)$
So:
$$
= \frac{3(q+4)(q+4) - 2(q-7)(5-q)}{(5-q)(q+4)}
$$
Wait — careful: first term is $\frac{3(q+4)}{5-q}$, so numerator is $3(q+4)$ times $(q+4)$? No!
Actually:
$$
\frac{A}{B} - \frac{C}{D} = \frac{A \cdot D - C \cdot B}{B \cdot D}
$$
So:
$$
= \frac{3(q+4)(q+4) - 2(q-7)(5-q)}{(5-q)(q+4)}
$$
Wait — no! First fraction: numerator is $3(q+4)$, denominator $5 - q$
Second: numerator $2(q-7)$, denominator $q+4$
So:
$$
= \frac{3(q+4) \cdot (q+4) - 2(q-7) \cdot (5 - q)}{(5 - q)(q + 4)}
$$
Yes:
$$
= \frac{3(q+4)^2 - 2(q-7)(5 - q)}{(5 - q)(q + 4)}
$$
Now expand:
- $(q+4)^2 = q^2 + 8q + 16$, so $3(q^2 + 8q + 16) = 3q^2 + 24q + 48$
- $(q-7)(5 - q) = q(5 - q) - 7(5 - q) = 5q - q^2 - 35 + 7q = -q^2 + 12q - 35$
Then multiply by 2: $-2q^2 + 24q - 70$
Now subtract: $3q^2 + 24q + 48 - (-2q^2 + 24q - 70)$
Wait — in the formula: it's $A D - C B$, so:
$$
3(q+4)^2 - 2(q-7)(5 - q)
= (3q^2 + 24q + 48) - (-2q^2 + 24q - 70)
= 3q^2 + 24q + 48 + 2q^2 - 24q + 70
= 5q^2 + 118
$$
So numerator: $5q^2 + 118$
Denominator: $(5 - q)(q + 4)$
So:
$$
\boxed{\frac{5q^2 + 118}{(5 - q)(q + 4)}}
$$
Alternatively, write $5 - q = -(q - 5)$, so:
$$
= \frac{5q^2 + 118}{-(q - 5)(q + 4)} = -\frac{5q^2 + 118}{(q - 5)(q + 4)}
$$
But unless factoring helps, leave as:
✔ Answer: $\boxed{\frac{5q^2 + 118}{(5 - q)(q + 4)}}$
---
4)
$$
\frac{2(1 - x)}{x + 2} + \frac{2x}{x + 7}
$$
Simplify first: $2(1 - x) = 2 - 2x$, so:
$$
= \frac{2 - 2x}{x + 2} + \frac{2x}{x + 7}
$$
Factor numerator: $2(1 - x)$
But $1 - x = -(x - 1)$, so:
$$
= \frac{-2(x - 1)}{x + 2} + \frac{2x}{x + 7}
$$
Now common denominator: $(x + 2)(x + 7)$
$$
= \frac{-2(x - 1)(x + 7) + 2x(x + 2)}{(x + 2)(x + 7)}
$$
Expand numerator:
First: $-2(x - 1)(x + 7)$
- $(x - 1)(x + 7) = x^2 + 7x - x - 7 = x^2 + 6x - 7$
- Multiply by -2: $-2x^2 - 12x + 14$
Second: $2x(x + 2) = 2x^2 + 4x$
Add together:
$$
(-2x^2 - 12x + 14) + (2x^2 + 4x) = (-2x^2 + 2x^2) + (-12x + 4x) + 14 = -8x + 14
$$
So:
$$
\boxed{\frac{-8x + 14}{(x + 2)(x + 7)}}
$$
Factor numerator: $-2(4x - 7)$ or $2(-4x + 7)$
So:
$$
= \frac{2(7 - 4x)}{(x + 2)(x + 7)}
$$
✔ Answer: $\boxed{\frac{2(7 - 4x)}{(x + 2)(x + 7)}}$
---
5)
$$
\frac{5 - x}{y + 3} + \frac{2y}{x}
$$
Different variables — no common factors.
Common denominator: $x(y + 3)$
$$
= \frac{(5 - x)x + 2y(y + 3)}{x(y + 3)}
$$
Expand numerator:
- $(5 - x)x = 5x - x^2$
- $2y(y + 3) = 2y^2 + 6y$
Add: $5x - x^2 + 2y^2 + 6y$
Arrange: $-x^2 + 5x + 2y^2 + 6y$
So:
$$
\boxed{\frac{-x^2 + 5x + 2y^2 + 6y}{x(y + 3)}}
$$
No further simplification possible.
✔ Answer: $\boxed{\frac{-x^2 + 5x + 2y^2 + 6y}{x(y + 3)}}$
---
6)
$$
\frac{3(a+4)}{b+2} - \frac{2(a-7)}{b+4}
$$
Different denominators: $b+2$, $b+4$
Common denominator: $(b+2)(b+4)$
$$
= \frac{3(a+4)(b+4) - 2(a-7)(b+2)}{(b+2)(b+4)}
$$
Expand numerator:
First: $3(a+4)(b+4)$
- $(a+4)(b+4) = ab + 4a + 4b + 16$
- Multiply by 3: $3ab + 12a + 12b + 48$
Second: $2(a-7)(b+2)$
- $(a-7)(b+2) = ab + 2a - 7b - 14$
- Multiply by 2: $2ab + 4a - 14b - 28$
Now subtract:
$$
(3ab + 12a + 12b + 48) - (2ab + 4a - 14b - 28)
= 3ab - 2ab + 12a - 4a + 12b + 14b + 48 + 28
= ab + 8a + 26b + 76
$$
So:
$$
\boxed{\frac{ab + 8a + 26b + 76}{(b+2)(b+4)}}
$$
Can this be factored? Let's see:
Numerator: $ab + 8a + 26b + 76$
Try grouping:
= $a(b + 8) + 2(13b + 38)$ — doesn't help.
Or: $a(b + 8) + 26b + 76$
Not factorable easily.
So leave as is.
✔ Answer: $\boxed{\frac{ab + 8a + 26b + 76}{(b+2)(b+4)}}$
---
✔ Final Answers Summary:
1) $\boxed{\frac{15x - 17}{(x-3)(x+1)}}$
2) $\boxed{\frac{5w^2 + 26w - 31}{(w-5)(3w+1)}}$
3) $\boxed{\frac{5q^2 + 118}{(5 - q)(q + 4)}}$
4) $\boxed{\frac{2(7 - 4x)}{(x + 2)(x + 7)}}$
5) $\boxed{\frac{-x^2 + 5x + 2y^2 + 6y}{x(y + 3)}}$
6) $\boxed{\frac{ab + 8a + 26b + 76}{(b+2)(b+4)}}$
Let me know if you'd like any of them checked further!
Parent Tip: Review the logic above to help your child master the concept of adding and subtracting algebraic fractions worksheet.