If x ¤ y = (x + y)^2 - (x - y)^2. Then √5 ¤ √5 = Choices.
A) 0	B) 5	C) 10	D) 15	E) 20
X = √5 and Y also =√5   Applying the function (√5+√5)^2 - (√5-√5)^2 = (2√5)^2 - 0 = 4 x 5 = 20.   Note: Alternative Approach is the entire function is represented as X^2 - Y^2 = (X+Y)(X-Y) which can be simplified as (x+y+x-y)(x+y-(x-y)) = (2x)(2y)=4xy. Substituting x=√5 and y = √5 you get the answer 20   Answer is 20.
<result>E</result>
If x ¤ y = (x + y)^2 - (x - y)^2. Then √5 ¤ √5 =