Given the following systems of equations match the first step needed to solve them by substitution. System A x - y = 12 2x - y =12 [ Select] [ Select] Solve the first equation for x, by adding y to both sides Solve the first equation for y. by adding x to both sides Solve the second equation for x by dividing it by 2 2x - y - 3 [ Select] To play audio version of question click the play button or click here