Question

rút gọn
A = ( x^2 - 8 )( x+1) - ( x - 2)(x^2 + 2x + 4 )

Answer 1

x^3 + x^2 - 8x - 8 - x^3 - 2x^2 - 4x + 2x^2 + 4x +8
=x^2 -12 x
100000000000% nha !!!

Answer 2

A = (x² - 8)(x + 1) - (x - 2)(x² + 2x + 4)

= x³ + x² - 8x - 8 - (x³ - 8)

= x³ + x² - 8x - 8 - x³ + 8

= x² - 8x= x(x - 8)

Answer 3

= x³+x²-8x-8-x³+2x²+4x-2x²-4x-8
=3x²