Question 395373
remember: Difference of Squares {{{a^2- b^2  =(a+ b)(a - b)}}} or {{{(a - b)(a + b)}}}

you apply it  here


{{{(4sqrt(x) + 4sqrt(y)) * (4sqrt(x) - 4sqrt(y)) }}}


{{{ ((4sqrt(x) )^2- (4sqrt(y))^2) }}}


{{{ 4^2(sqrt(x) )^2- 4^2(sqrt(y))^2) }}}


{{{ 16x- 16y }}}


{{{ 16(x- y )}}}