How do I solve x+y=1 and 5x-4y=-7?
Use substitution method:x + y = 1 --> y = x - 1 (then plug in to other equation)5x - 4y = -7 --> 5x - 4(x - 1) = -7 -->5x -4x + 4 = -7 --> x = -11 (then plug into one of original equations to find y)x + y = 1 --> (-11) + y = 1 --> y = 12