xy=1 then what is (7^(x+y)^2) / (7^(x-y)^2)	Pick.
A) 2401 B) 4 C) 8 D) 16 E) 32

Rationale: "( x + y ) ^ 2 - ( x - y ) ^ 2 ( x + y + x - y ) ( x + y - x + y ) ( 2 x ) ( 2 y ) 4 xy 4 7 ^ 4 = 2401 answer a"
Answer: A