Question

Solve for x: |3x + 12| = 18

A. x = 2, x = –10 
B.x = 2, x = –2 
C.x = 10, x = –10
D.x = –2, x = 10
help

Answer 1

`|3x+12|=18\iff3x+12=18\ \vee\ 3x+12=-18\\\\\text{Subtract 12 from both sides}\\\\3x=6\ \vee\ 3x=-30\qquad\text{divide both sides by 3}\\\\\boxed{x=2\ \vee\ x=-10}\to\boxed{A.}`