Question 107850
Your first problem was with the sign on the 3y term in your first step.


{{{2x-3y=12}}}
{{{-3y=12-2x}}}:  The minus sign needs to stay with the 3y term.
{{{y=(12-2x)/-3}}}:  Divide by -3
{{{y=-4+2x/3}}}:  Or you can write this more neatly as:
{{{y=2x/3-4}}}