The first thing you should know is that you have a system of two equations with two unknowns. Clearing we have: y-x = 9 2y + 2x = -10 Step1: multiply equation 1 by -2 -2y + 2x = -18 2y + 2x = -10 Step2: add both equations: 4x = -28 x = -28 / 4 = -7 answer The x-coordinate of the solution for the system of equations is x = -7
