\(a.\left(x^2-3x+2\right)\left(x-2\right)\)
\(=x^3-2x^2-3x^2+6x+2x-4\)
\(=x^3-5x^2+8x-4\)
b. Từ kết quả ở câu a, ta có:
\(\left(x^2-3x+2\right)\left(x-2\right)\)
\(=\left(-x^2-3\left(-x\right)+2\right)\left(2-\left(-x\right)\right)\) (ta thay x bằng -x nha)
\(=\left(-x^2+3x+2\right)\left(2+x\right)\)
\(=-2x^2-x^3+6x+3x^2+2+2x\)
\(=-x^3+x^2+8x+2\)