$f(x)=x(2x^2-5x-7)$

How would you rewrite $f(x)$ so it can be differentiated using the power rule?

Choose $1$ answer:

$\frac{2x^2-5x-7}{x^{-1}}$

$x(x+1)(2x-7)$

$2x^3-5x^2-7x$

This is not possible.