Question

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

Answer 1

$|3x+12|=18\iff3x+12=18\ or\ 3x+12=-18\\subtract\ 12\ from\ both\ sides\\\\3x=6\ or\ 3x=-30\ \ \ \ |divide\ both\ sides\ by\ 3\\\\\huge\boxed{x=2\ or\ x=-10}$

Answer 2

|3x+12|=18

Solve Absolute Value.

|3x+12|=18

3x+12=18 or 3x+12=−18

3x+12=18(Possibility 1)

3x+12−12=18−12(Subtract 12 from both sides)

3x=6

3x3=63(Divide both sides by 3)

x=2

3x+12=−18(Possibility 2)

3x+12−12=−18−12(Subtract 12 from both sides)

3x=−30

3x3=−303(Divide both sides by 3)

x=−10

The answer is:

x=2 or x=−10