using elimination method, solve this, -16y+9x=63 16y-28x=-196

-16y+9x=  63

16y-28x=-196        add the two equations......this produces.......

-19x =  -133     divide both sides by -19

x = 7           and we can use either equation to find y.....so.....

-16y + 9(7)  =  63

-16y + 63 = 63      subtract 63 from both sides

-16y = 0        and it's clear that y must = 0