Question

Mọi người có thể giúp em với ạ em đang cần gấp lắm

Answer 1

13: \(=x^3-3x^2+3x-1-x-2=x^3-3x^2+2x-3\)

14: \(=x^3+15x^2+75x+125-3x^2-6x-3\)

\(=x^3+12x^2+69x+122\)

Answer 2

\(13.\\ \left(x-1\right)^3-\left(x+2\right)=x^3-3x^2.1+3x.1^2-1^3-x-2\\ =x^3-3x^2+3x-1-x-2\\ =x^3+3x^2+3x-x-3\)

\(14.\\ \left(x+5\right)^3-3\left(x+1\right)^2=x^3+3x^2.5+3x.5^2+5^3-3\left(x^2+2x+1\right)\\ =x^3+15x^2+75x+125-3x^2-6x-3\\ =x^3+12x^2+69x+122\)

\(15.\\ \left(2x+1\right)\left(4x^2-2x+1\right)-3x^2\left(x-2\right)=\left(2x\right)^3+1-3x^3+6x^2\\ =8x^3+1-3x^3+6x^2=5x^3+6x^2+1\)