If x/y =1/3, then value of (x2+y2)/(x2-y2) is-
A
-10/9
B
5/4
C
-5/4
D
-5/3
Correct Answer: -5/4
xy = 13 x2y2 = 19 x2+y2x2-y2 = 1+91-9 = 10-8 = -54 (Ans)