Question

Упростите выражение
(5c+7d)^2-70cd

Answer 1

$(5c+7d)^2-70cd=(5c)^2+(7d)^2+2*5c*7d-70cd=$$25c^2+49d^2+70cd-70cd=25c^2+49d^2$

Answer 2

(5c+7d)^2-70cd=25c^2+70cd+49d^2-70cd=25c^2+49d^2