7 Класс №1 (с-7)(с+7)= (7х-2)(7х+2)= (10р-6q)(10р+6q)= №2 (-a+b)(b-a)= (a+b)(-a-b)= (-a-b)(-a-b)=
№1 1) = с^2+7c-7c-49=c^2-49 2) = 49x^2+14x-14x-4=49x^2-4 3) = 100p^2+60pq-60pq-36q^2=100p^2-36q^2 №2 1) = -ab-a^2+b^2-ab=b^2-a^2-2ab 2) = -a^2-ab-ab+b^2=b^2-a^2-2ab 3) = a^2+ab+ab+b^2=a^2+b^2+2ab