Answer:
1. a = -6
4 = 2(a + 8)
Divide both sides by 2.
= a + 8
Divide 4 by 2 to get 2.
2 = a + 8
Swap sides so that all variable terms are on the left-hand side.
a + 8 = 2
Subtract 8 from both sides.
a = 2 - 8
Subtract 8 from 2 to get −6.
a = -6
2. y = -3
−4(3+y)=12(−3−y)
Use the distributive property to multiply −4 by 3+y.
−12−4y=12(−3−y)
Use the distributive property to multiply 12 by −3−y.
−12−4y=−36−12y
Add 12y to both sides.
−12−4y+12y=−36
Combine −4y and 12y to get 8y.
−12+8y=−36
Add 12 to both sides.
8y=−36+12
Add −36 and 12 to get −24.
8y=−24
Divide both sides by 8.
y =

Divide −24 by 8 to get −3.
y = -3
3. c = 2
−6+7c=2(c+2)
Use the distributive property to multiply 2 by c+2.
−6+7c=2c+4
Subtract 2c from both sides.
−6+7c−2c=4
Combine 7c and −2c to get 5c.
−6+5c=4
Add 6 to both sides.
5c=4+6
Add 4 and 6 to get 10.
5c=10
Divide both sides by 5.
c =

Divide 10 by 5 to get 2.
c = 2
4. a = 1
−(a−9)=8a
To find the opposite of a−9, find the opposite of each term.
−a−(−9)=8a
The opposite of −9 is 9.
−a+9=8a
Subtract 8a from both sides.
−a+9−8a=0
Combine −a and −8a to get −9a.
−9a+9=0
Subtract 9 from both sides. Anything subtracted from zero gives its negation.
−9a=−9
Divide both sides by −9.
a =

Divide −9 by −9 to get 1.
a = 1
5. x = 27
7x=−3(−2x−9)
Use the distributive property to multiply −3 by −2x−9.
7x=6x+27
Subtract 6x from both sides.
7x−6x=27
Combine 7x and −6x to get x.
x=27
6. p = 9
2(3p−7)=40
Divide both sides by 2.
3p−7=

Divide 40 by 2 to get 20.
3p−7=20
Add 7 to both sides.
3p=20+7
Add 20 and 7 to get 27.
3p=27
Divide both sides by 3.
p=

Divide 27 by 3 to get 9.
p=9
7. a = -8
4a+77−5(1−a)=0
Use the distributive property to multiply −5 by 1−a.
4a+77−5+5a=0
Subtract 5 from 77 to get 72.
4a+72+5a=0
Combine 4a and 5a to get 9a.
9a+72=0
Subtract 72 from both sides. Anything subtracted from zero gives its negation.
9a=−72
Divide both sides by 9.
a=

Divide −72 by 9 to get −8.
a=−8
8. x = -1
2(x−7)=−2(x+9)
Use the distributive property to multiply 2 by x−7.
2x−14=−2(x+9)
Use the distributive property to multiply −2 by x+9.
2x−14=−2x−18
Add 2x to both sides.
2x−14+2x=−18
Combine 2x and 2x to get 4x.
4x−14=−18
Add 14 to both sides.
4x=−18+14
Add −18 and 14 to get −4.
4x=−4
Divide both sides by 4.
x=

Divide −4 by 4 to get −1.
x=−1
Hope it helps and have a great day!
=D ~sunshine~