Data Sufficiency (DS) | Re: What is the value of x^2 y^2 ?

We need to find x^2 - y^2 = (x-y) (x+y)

(A) x - y = -1 , Not suff.

(B) 5x - 5y = 1/(2x + 2y)

5 (x-y) * 2(x+y) = 1
10 (x-y) (x+y) =1
(x-y) (x+y) = 1/10
Sufficient.

answer is Option B.