{x+y=7
{2x^2-y^2=2
y=7-x
2x^2-(7-x)^2=2
2x^2-49+14x-x^2=2
x^2+14x-49=2
x^2+14x-51=0
x1=-17
x2=3
y1=24
y2=4
{x+y=7
{2x^2-y^2=2
y=7-x
2x^2-(7-x)^2=2
2x^2-49+14x-x^2=2
x^2+14x-49=2
x^2+14x-51=0
x1=-17
x2=3
y1=24
y2=4