Question

This is a briliant question

Answer 1

Here,
you can do one thing ,Squaring both sides
(y-x)^2 = 1^2
y^2 + x^2 -2xy = 1

Now, subtract this equation from the given one
you will get
xy = 2.
Put the value of xy in the equation 1 to get the value of x^2+y^2 i.e you will get 5.
Thus, Solution will be 2/5.