Question

спростіть вираз(-2a-b)²-(a-b)²

Answer 1

(-2а-в)²-(а-в)²=4а²+4ав+в²-(а²-2ав+в²)=4а²+4ав+в²-а²+2ав-в²=3а²+6ав.

Answer 2

(-2a - b)² - (a - b)² = (-2a - b + a - b)(-2a - b - a + b) = (-a - 2b)(-3a) =

                             = 3a² + 6ab = 3a(a + 2b);