x = 8
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-4x' to each side of the equation.
72 + 9x + -4x = 112 + 4x + -4x
Combine like terms: 9x + -4x = 5x
72 + 5x = 112 + 4x + -4x
Combine like terms: 4x + -4x = 0
72 + 5x = 112 + 0
72 + 5x = 112
Add '-72' to each side of the equation.
72 + -72 + 5x = 112 + -72
Combine like terms: 72 + -72 = 0
0 + 5x = 112 + -72
5x = 112 + -72
Combine like terms: 112 + -72 = 40
5x = 40
Divide each side by '5'.
x = 8