(X+y)2-(x-y)2 (4p-q)2-(2p+3q)2
(х+у+х-у)(х+у-х+у)=2х*2у=4
(4p-q+2p+3q)(4p-q-2p-3q)=(6p+2q)(2p-4q)=4(3p+q)(p-2q)