1: Solve for either x or y in one of the equations. So x + y = -1 is y = -x -1 2: substitute the new equation in the opposite equation. So x - (-x - 1) = 7 3: distribute the negative. X + x + 1 = 7 4: combine like terms. 2x + 1 = 7 5: solve for x. Subtract 1 on both sides. 2x = 6 6: divide by 2 to get x by itself. X = 3 7: plug the new value of x into one of the ORIGINAL equations. 3 + y = -1 8: solve for y. Subtract 3 on both sides. Y = -4 9: the solution is written as (x,y) so the solution would be (3, -4)
