Question

phan tich da thuc thanh nhan tu

x³ -2x -4

Answer 1

\(x^3-2x-4\)

\(=x^3-4x+2x-4\)

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

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

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

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

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

Answer 2

x^3-2x-4

=x^3-4x+2x-4

=(x^3-4x)+(2x-4)

=x(x^2-4)+2(x-2)

=x(x+2)(x-2)+2(x-2)

=(x-2)[(x(x+2)+2]

=(x-2)(x^2+2x+2)