Найдите произведение многосленов : (3х+2у)(х-у); (5b-4с)(2b-2с) ; (р-3q)(8р+5q)

(3x+2y)(x-y)=3x²-3xy+2xy-2y²=3x²-xy-2y²
(5b-4c)(2b-2c)=10b²-10bc-8bc+8c²=10b²-18bc+8c²
(p-3q)(8p+5q)=8p²+5pq-24pq-15q²=8p²-19pq-15q²