What's the solution for 2x 7y=2 x y=-1

Simplifying

(2x + -7y ) = 0

Multiply
(2x + -7y) * (x + y)
(2x * (x + y) + -7y * (x + y)) = 0
((x * 2x + y * 2x) + -7y * (x + y)) = 0

Reorder the terms:
((2xy + 2x2) + -7y * (x + y)) = 0
((2xy + 2x2) + -7y * (x + y)) = 0
(2xy + 2x2 + (x * -7y + y * -7y)) = 0
(2xy + 2x2 + (-7xy + -7y2)) = 0

Reorder the terms:
(2xy + -7xy + 2x2 + -7y2) = 0

Combine like terms: 2xy + -7xy = -5xy
(-5xy + 2x2 + -7y2) = 0

Solving -5xy + 2x2 + -7y2 = 0

Solving for variable 'x'.

Factor a trinomial. 
(2x + -7y)(x + y) = 0