Which of the following values is a solution of 3|5 + x| = 12?

A. 7

B. 1

C. - 9

D. - 17

It is easiest to simply just substitute any of the choices into the original equation and see which one satisfies the equation.

Given the equation: 3 * |5 + x| = 12

Using choice A. x = 7

3 * |5 + 7| = 12

36 = / = 12

Using choice B. x = 1

3 * |5 + 1| = 12

18 = / = 12

Using choice C. x = - 9

3 * |5 + - 9| = 12

12 = 12

Therefore, the correct answer is C. - 9