Q:

If $p(x+y)^2=5$ and $q (x-y)^2=3$, then the simplified value of $p^2(x+y)^2+4pqxy-q^2(x-y)^2$ is?

If $p(x+y)^2=5$ and $q (x-y)^2=3$, then the simplified value of $p^2(x+y)^2+4pqxy-q^2(x-y)^2$ is?

Answer: $2(p+q)$

A:

$$(x+y)^2 = 5/p$$
$$(x-y)^2 = 3/q$$
$$\implies 4xy = 5/p - 3/q$$

