Answer:
x = 12
Explanation:
5x + 4x - 27 = 81
Combine the terms with x on the left side: 5x + 4x = 9x
9x - 27 = 81
Add 27 to both sides.
9x - 27 + 27 = 81 + 27
-27 + 27 = 0, and 81 + 27 = 108.
9x = 108
Divide both sides by 9.
9x/9 = 108/9
Do the operations on both sides. 9x/9 = x; 108/9 = 12
x = 12