Question

How do you factor `9x - 64x^3`?

Answer 1

We have `9x - 64x^3 = f(x)`

`implies f(x) = x(9-64x^2)`
`implies f(x) = x(3^2 - (8x)^2)`
`implies f(x) = x(3 + 8x)(3 - 8x)`

And that's it.

`9x - 64x^3 = x(3 + 8x)(3 - 8x)`