Question

If x+y =1 and x^2+y^2=2, what is x/y+y/x?

Answer 1

if x+ y = 1 then that means x = 1 - y

substitute that

x^2 + y^2 = 2

(1-y)^2 + y^2 = 2
1 - 2y + y^2 + y^2 = 2
1 - 2y + 2y^2 = 2
-2 + 1 - 2y + 2y^2 = 0
2y^2 - 2y - 1 = 0

you have to use quadratic formula to find y now