Question

Wykonaj działania:
a) -3x(x-1)(x-2)-9x2 ( do 9x do kwadrat)
b) (a+2c)(a-c+2)-ac
c) (a - c)(2a+c-3)+ac

proszę o szybka odpowiedź

Answer 1

a)
-3x(x-1)(x-2)-9x2 ( do 9x do kwadrat) =
= (-3x² + 3x)(x - 2) - 9x² = -3x³ + 6x² + 3x² - 6x - 9x² =
= -3x³- 6x
b)
(a+2c)(a-c+2)-ac =
= a² - ac + 2a + 2ac - 2c² + 4c - ac =
= a² + 2a - 2c² + 4c = a(a + 2) - 2c(c - 2)
c)
(a - c)(2a+c-3)+ac =
= 2a² + ac - 3a - 2ac - c² + 3c + ac =
= 2a² - 3a - c² + 3c

Answer 2

-3x(x-1)(x-2)-9x² = (-3x²+3x)(x-2) - 9x² = -3x³ + 6x² + 3x² - 6x - 9x² = -3x³- 6x 

(a+2c)(a-c+2)-ac= (a-c+2)(a+2c) - ac = a² + 2ac - ac - 2c² + 2a + 4c - ac = a² - 2c² + 4c + 2a

(2a+c-3)(a-c)+ac= 2a² - 2ac + ac - c² -3a + 3c + ac = 2a² - c² - 3a + 3c