Question Number 100792 by bramlex last updated on 28/Jun/20

Answered by bobhans last updated on 28/Jun/20

((x+xy)/y) = ((y+xy)/x) ⇒ x^2 +x^2 y = y^2 +xy^2   x^2 −y^2  = xy^2 −x^2 y ; (x−y)(x+y)=−xy(x−y)  ⇒ x+y = −xy . Then (1/x) + (1/y) = ((x+y)/(xy)) = −1 ★