Question

Phân tích đa thức thành nhân tử:

a)x⁴ - 4x² - 8x²+ 8x 

b)x² - 1 - xy + y

c)(x-1)(x-2)(x-3) + (x-1)(x-2)(x-1)

Answer 1

a: \(x^4-4x^3-8x^2+8x\)

\(=x\left(x^3-4x^2-8x+8\right)\)

\(=x\left[\left(x+2\right)\left(x^2-2x+4\right)-4x\left(x+2\right)\right]\)

\(=x\left(x+2\right)\left(x^2-6x+4\right)\)

b: \(x^2-1-xy+y\)

\(=\left(x-1\right)\left(x+1\right)-y\left(x-1\right)\)

\(=\left(x-1\right)\left(x-y+1\right)\)

c: Ta có: \(\left(x-1\right)\left(x-2\right)\left(x-3\right)+\left(x-1\right)^2\cdot\left(x-2\right)\)

\(=\left(x-1\right)\cdot\left(x-2\right)\cdot\left(x-3-x-1\right)\)

\(=2\cdot\left(x-1\right)\cdot\left(x-2\right)^2\)