If x+y=25 and x2y3 + y2x3=25, what is the value of xy?
Choose the correct choice from the following choices.
A) 1	B) 2	C) 3	D) 4	E) 5

Rationale: xy = 1 as x + y = 25 x 2 y 3 + y 2 x 3 = 25 x 2 y 2 ( y + x ) = 25 substituting x + y x 2 y 2 = 1 xy = 1 answer : a
Answer: A