5x-9=y,3x-4y=-7;
5x-9-(3x-4y)=y-(-7);
5x-9-3x+4y=y+7;
2x+4y-9=y+7;
x=(16-3y)/2;
5((16-3y)/2)-9=y
y=62/17;
x=43/17.