Question

Phân tích đa thức

a/ x³-7x+6

x³-7x-6

Answer 1

a/ \(x^3-7x+6\)

\(=x^3-x^2+x^2-x-6x+6\)

\(=x^2\left(x-1\right)+x\left(x-1\right)-6\left(x-1\right)\)

\(=\left(x-1\right)\left(x^2+x-6\right)\)

\(=\left(x-1\right)\left(x^2-2x+3x-6\right)\)

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

b/ \(x^3-7x-6\)

\(=x^3+x^2-x^2-x-6x-6\)

\(=x^2\left(x+1\right)-x\left(x+1\right)-6\left(x+1\right)\)

\(=\left(x+1\right)\left(x^2-x-6\right)\)

\(=\left(x+1\right)\left(x^2+2x-3x-6\right)\)

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

Answer 2

\(a,x^3-7x+6=\left(x+3\right)\left(x-2\right)\left(x-1\right)\)