Solve for a in the problem:

-3 (9a+2) = 129

Answer: a = - 5

Step-by-step explanation:

-3 (9a+2) = 129

-27a - 6 = 129

-27a = 129+6

-27a = 135

a = - 135/27

a = - 5

Step-by-step explanation:

To solve the equation, we want to find out what a is. In order to do this, we have to get a by itself. Perform the opposite of what is being done to the equation. Keep in mind, everything done to one side, has to be done to the other.

-3 (9a+2) = 129

-3 is being multiplied by 9a+2. The opposite of multiplication is division, so divide both sides by - 3.

-3 (9a+2) / -3=129/-3

9a+2=129/-3

9a+2=-43

2 is being added on to 9a. The opposite of addition is subtraction, so subtract 2 from both sides.

9a+2-2 = - 43-2

9a = - 43-2

9a = - 45

a is being multiplied by 9. The opposite of multiplication is division, so divide both sides by 9.

9a/9 = - 45/9

a = - 45/9

a=-5