x^2+x-xy-xy+y^2+y=10 (le am adunat intre ele)
x^2-2xy+ y^2+x+y=10
(x-y)^2+x+y=10
x+y=10-(x-y)^2
10-(x-y)^2-xy=3 (am inlocuit in a doua ecuatie)
10-x^2+xy-y^2-xy=3
-x^2-y^2+10=3
-x^2-y^2=-7
x^2+y^2=7=> xy=0 => x+y=3=>x=3-y
<=> (3-y)^2+y^2=7
9-6y+y^2+y^2=7
2y^2-6y+9-7=0
2y^2-6y+2=0
delta=36-16=20
y1=(6-2radical din 5)/4=(3-radical din 5)/2
y2=(3+radical din 5)/2
nu stiu daca e corect, dar la asta m am gandit eu
