Firstly, label each of our equations: y - 2x = 6 (1) y + 2x = 0 (2)Then we can rearrange (2) to get the following: y = -2x (3)Then, substitute (3) into (1): -2x - 2x = 6Which yields the result: -4x = 6Therefore: x = -1.5We can now substitute this result into any of our previous equations to get y. Therefore: y = 3