Question 33891
all you need to do is use the FOIL method
{{{(x^2+2y)(x^2-2y)}}}
   F:x^2 * x^2 = 0
   O:x^2 * -2y = -2x^2*y
   I:x^2 * +2y = +2x^2*y
   L:-2y * +2y = 0
and you are left with 
{{{x^2}}}

good luck!
Anjanie