Question

Спростити вираз
1) (3х-4)(2х+3) - (х+2)(х+5) =
2) (х+2)(х+11) -2х(3х-4х) =
3) (y-9)(3y-1) - (2y+1)(5y-7) =

Answer 1

1) = 6х² - 8х + 9х - 12 - х² - 2х - 5х - 10 = (6х² - х²) + (-8х + 9х - 2х - 5х) + (-12 - 10) = 5х² -6х - 22;

2) = х² + 2х + 11х + 22 - 6х² + 8х² = (х² - 6х² + 8х²) + (2х + 11х) + 22 = 3х² + 13х + 22;

3) = 3у² - 27у - у + 9 - 10у² - 5у + 14у + 7 = (3у² - 10у²) + (-27у - у - 5у + 14у) + (9 + 7) = -7у² - 19у + 16.