Question

Solve the equations:
4x^2-5xy+y^2=10,
3x^2-3xy-y^2=5.
.
.
ANSWER = {(1,-1),(-1,1),(3,2),(-3,-2)}

Answer 1

can somebody explain what has he done

Answer 2

i guess no one bothers to help me

Answer 3

2 times second one - first one\[2(3x^2-3xy-y^2)-(4x^2-5xy+y^2)=2\times5-10=0\]\[2x^2-xy-3y^2=0\]\[(2x-3y)(x+y)=0\]\[2x=3y\]or\[x=-y\]