\(\left(x-2\right)^3+\left(2x+1\right)^2+2\left(x+2\right)\left(1-x\right)-9x^3+2x\)
\(=x^3-6x^2+12x-8+8x^3+12x^2+6x+1+2\left(x+2\right)\left(1-x\right)-9x^3+2x\)
\(=9x^3+6x^2+18x-7+2\left(x-x^2+2-2x\right)-9x^3+2x\)
\(=6x^2+20x-7-2x^2-2x+4=4x^2+18x-3\)
Trả lời:
( x - 2 )3 + ( 2x + 1 )3 + 2 ( x + 2 )( 1 - x ) - 9x3 + 2x
= x3 - 6x2 + 12x - 8 + 8x3 + 12x2 + 6x + 1 + 2 ( x - x2 + 2 - 2x ) - 9x3 + 2x
= 9x3 + 6x2 + 18x - 7 + 2x - 2x2 + 4 - 4x - 9x3 + 2x
= 4x2 + 18x - 3
