{x-y=7 {x^2+y^2=9-2xy

Question

{x-y=7 {x^2+y^2=9-2xy

Answer 1

x^2+y^2=9-2xy -> (x+y)^2=9

 

1) x+y=3; x-y=7

x=5, y=-2

2) x+y=-3; x-y=7

x=2, y=-5