Question

Cần gấp

Answer 1

a) (x - 3) ( x + 3) - ( 3x + 2)²

=> x² - 3² - (9x² + 12x + 4)

=> x² - 9 - 9x² - 12x - 4

=> - 8x² - 12x - 13

b) (x + 1) ( x- 1) -  (2x - 5)²

=> x² - 1 - (4x² - 20x + 25)

=> x² - 1 - 4x² + 20x - 25

=> - 3x² + 20x - 26

c) (x - 3 )² - (x + 2)² - (x + 6 ) (x - 5)

=> x² - 6x + 9 - ( x² + 4x + 4) - ( x² - 5x + 6x - 30)

=> x² - 6x + 9 - x² - 4x - 4 - x² + 5x - 6x + 30 

=> - x² - 11x + 35

d) (x + 2 )³ - (x - 2)²

=> x³ + 6x² + 12x + 8 - (x² - 4x + 4)

=> x³ + 6x² + 12x + 8 - x² + 4x - 4

=> x³ + 5x³ + 16x + 4

Answer 2

a)

\(=x^2-3^2-\left(\left(3x\right)^2+2.3x.2+2^2\right)\)

\(=x^2-9-\left(9x^2+12x+4\right)\)

\(=x^2-9-9x^2-12x-4\)

\(=-8x^2-12x-13\)