Let’s solve each problem step by step. We’ll simplify each algebraic expression by combining like terms and using the distributive property where needed.
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1) 5(a + 6) - 2(7a + 5)
First, distribute:
- 5 × a = 5a
- 5 × 6 = 30
- -2 × 7a = -14a
- -2 × 5 = -10
Now write it all out:
5a + 30 - 14a - 10
Combine like terms:
- (5a - 14a) = -9a
- (30 - 10) = 20
→
-9a + 20
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2) 10y + 36 - 38y - 47
Group y terms and constants:
- (10y - 38y) = -28y
- (36 - 47) = -11
→
-28y - 11
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3) -8(-5x + 7) + 5x
Distribute -8:
- -8 × -5x = 40x
- -8 × 7 = -56
So: 40x - 56 + 5x
Combine x terms: 40x + 5x = 45x
→
45x - 56
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4) -8(x - 6) + 20(x + 10)
Distribute both:
- -8 × x = -8x
- -8 × -6 = +48
- 20 × x = 20x
- 20 × 10 = 200
Write it out: -8x + 48 + 20x + 200
Combine x terms: (-8x + 20x) = 12x
Constants: 48 + 200 = 248
→
12x + 248
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5) -2x + (3/2)x
We need to combine these. Think of -2x as -4/2 x.
So: -4/2 x + 3/2 x = (-4 + 3)/2 x = -1/2 x
→
-½x or
-\frac{1}{2}x
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6) -6x + 8(3 - 8x)
Distribute 8:
- 8 × 3 = 24
- 8 × -8x = -64x
So: -6x + 24 - 64x
Combine x terms: -6x - 64x = -70x
→
-70x + 24
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7) (5/7)(-8/5 k + 1)
Distribute 5/7 to both terms inside:
First term: (5/7) × (-8/5 k)
Multiply numerators: 5 × -8 = -40
Denominators: 7 × 5 = 35
So: -40/35 k → simplify: divide numerator and denominator by 5 → -8/7 k
Second term: (5/7) × 1 = 5/7
→
-⁸⁄k + ⁵₇
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8) -8(2y) + 9 - 15 + 13y
First, multiply: -8 × 2y = -16y
Now rewrite: -16y + 9 - 15 + 13y
Group y terms: -16y + 13y = -3y
Constants: 9 - 15 = -6
→
-3y - 6
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9) 4(3t + 8) + 8
Distribute 4:
- 4 × 3t = 12t
- 4 × 8 = 32
So: 12t + 32 + 8
Add constants: 32 + 8 = 40
→
12t + 40
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10) 8x + 6 - 7x + 7 + 3x + 2
Group x terms: 8x - 7x + 3x = (8 - 7 + 3)x = 4x
Constants: 6 + 7 + 2 = 15
→
4x + 15
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Final Answer:
1) -9a + 20
2) -28y - 11
3) 45x - 56
4) 12x + 248
5) -½x
6) -70x + 24
7) -⁸₇k + ⁵⁄₇
8) -3y - 6
9) 12t + 40
10) 4x + 15
Parent Tip: Review the logic above to help your child master the concept of simplifying algebraic expressions worksheet 7th grade.