For the following system, if you isolated x in the first equation to use the substitution method, what expression would you substitute into the equation? -x-2y=-4 3x+y=12
Do you mean substitute into the second equation? If that is so -x = 2y - 4 x = -2y + 4 You could put this into the second equation. When you do 3(-2y + 4) + y = 12 -6y + 12 + y = 12 -5x =0 x = 0.