{x+5y=7
{3x+2y=-5
{x=7-5y
{21 -15y+2y=-5
{-13y=-26
{y=2
{x=-3
x=7-5y
3*(7-5y)+2y=-5
21-15y+2y=-5
21-13y=-5
13y= 21+5
13y=26
y=2
x+5*2=7
x+10=7
x=-3
(-3 :2)
{x+5y=7
{3x+2y=-5
{x=7-5y
{21 -15y+2y=-5
{-13y=-26
{y=2
{x=-3
x=7-5y
3*(7-5y)+2y=-5
21-15y+2y=-5
21-13y=-5
13y= 21+5
13y=26
y=2
x+5*2=7
x+10=7
x=-3
(-3 :2)