15. Which number from the replacement set {6, 12, 24} is a solution for the equation 3x + 12 = 36 − x?

6

Step-by-step explanation:

3x+12=36−x

Step 1: Simplify both sides of the equation.

3x+12=36−x

3x+12=36+−x

3x+12=−x+36

Step 2: Add x to both sides.

3x+12+x=−x+36+x

4x+12=36

Step 3: Subtract 12 from both sides.

4x+12−12=36−12

4x=24

Step 4: Divide both sides by 4.

4x/4 = 24/4

x=6

x=6