Question

A student solved s system of equations by elimination. Describe and correct the error made in the part of the solution shown.

5x+4y — x3→15x+12y=6

3x+3y — x4→12x+12y=-3

3x+0=9

x=3

Answer 1

It went wrong in the 2nd step. It doesn't equal -3 it equals positive 3