Question

How do you factor completely `x^3 - 9x`?

Answer 1

`x^3-9x=x(x+3)(x-3)`

Explanation:

`x^3-9x`

= `x(x^2-9)`

= `x(x^2-3^2)`

Now using identity `a^2-b^2=(a+b)(a-b)`, we get

`x(x^2-3^2)`

= `x(x+3)(x-3)`