To find the value of x, we may add 12 to both sides of the equation and subtract 4x from the answer. 8x - 12 + 12 = 4x + 24 + 12 8x - 4x = 4x - 4x + 36 4x = 36 Divide both left hand and right hand side of the equation by 4 to give an answer of x = 9.