x + 4 = 9x + 4 Subtract 9x from both sides: x + 4 = 9x + 4 -9x -9x ----------------- -8x + 4 = 4 Subtract 4 from both sides -8x + 4 = 4 - 4 -4 ----------- -8x = 0 Divide both sides by -8= Cancel the -8's on the left and 0 divided by -8 is 0: = 0 So we end up with just x = 0 Edwin