(3х-2у)(х-у)+(у-х)(2х+у) = (3х-2у)(х-у)-(x-y)(2х+у) = (x-y)(3х-2у-(2х+у)) =
(x-y)(3х-2у-2х-у) = (x-y)(x-3y)
(3х-2у)(х-у)+(у-х)(2х+у) = (3х-2у)(х-у)-(x-y)(2х+у) = (x-y)(3х-2у-(2х+у)) =
(x-y)(3х-2у-2х-у) = (x-y)(x-3y)