Упростите выражения: a) 3a(a+1)+(a+2)(a-3) b) (y-3)(5-y)-(4-y)(y+6)

Question

Упростите выражения: a) 3a(a+1)+(a+2)(a-3) b) (y-3)(5-y)-(4-y)(y+6)

Answer 1

А) 3a(a + 1) + (a + 2)(a - 3) = 3a² + 3a + a² - 3a + 2a - 6 = 4a² + 2a - 6 = 2(2a² + a - 3) = 2(a - 1)(2a + 3)

b) (y - 3)(5 - y) - (4 - y)(y + 6) = 5y - 15 - y² + 3y - 4y - 24 + y² + 6y = 10y - 39