Question

Solve for x: |3x|=12

Answer 1

Clear the absolute-value bars by splitting the equation into its two cases, one for the Positive case and the other for the Negative case.

The Absolute Value term is |x-3|

For the Negative case we'll use -(x-3)  

For the Positive case we'll use (x-3)  

Step  3  :

Solve the Negative Case

     -(x-3) = 12  

    Multiply

     -x+3 = 12  

    Rearrange and Add up

     -x = 9  

    Multiply both sides by (-1)  

     x = -9  

    Which is the solution for the Negative Case

Step  4  :

Solve the Positive Case

     (x-3) = 12  

    Rearrange and Add up

     x = 15  

    Which is the solution for the Positive Case

Step  5  :

Wrap up the solution

x=-9

x=15

Answer 2

Answer:

x = 4; x = -4

Step-by-step explanation:

|3x| = 12

3x = 12

3x/3 = 12/3

x = 4

3x = -12

3x/3 = -12/3

x = -4