Question

У простите выражение (3а-в)^2-(а^2+2в^2)

Answer 1

9а^2-6ав+в^2-а^2-2в^2=8а^2-6ав-1в^2

Answer 2

(3а-в)²-(а²+2в²)=(3а-в)(3а-в)-(а²+2в²)=9а²-3ав-3ав+в²-а²-2в²=
=8а²-6ав-в²