Question

(x+y+5)(x+y-5)

Answer 1

(x+y)^2 -25

Answer 2

we know that (\[a ^{2}-b ^{2}=(a+b)(a-b)\]
using this we get\[(x+y)^{2}-(5)^{2}=x ^{2}+y ^{2}+2xy-25\]