Solve.

4 (a+3) = 12+4a

A. - 3

B. - 1

C. No solution

D. All real numbers

4 (a + 3) = 12 + 4a Use the Distributive Property

4a + 12 = 12 + 4a Subtract 4a from both sides

12 = 12

Since the equation is the same on both sides, any number will work as a. So, the answer is D. All Real Numbers.