Here's how you would do it: 9x - 5 = 6x + 9x + 10 combine 6x and 9x 9x - 5 = 15x + 10 subtract 9x from both sides -5 = 6x + 10 subtract 10 from both sides -15 = 6x divide both sides by 6 -15/6 = x simplify the fraction -5/2 = x or in decimal form x = -2.5
