Factor: \(4bx^3 - 4bx^2 - 80bx\)

$$\begin{align}
4bx^3 - 4bx^2 - 80bx
&= 4bx(x^2 - x - 20) \\
&= 4bx(x - 5)(x + 4)
\end{align}$$

Factor: \(-3x^3 - 6x^2 + 72x\)

$$\begin{align}
-3x^3 - 6x^2 + 72x
&= -3x(x^2 + 2x + 24) \\
&= -3x(x + 6)(x - 4)
\end{align}$$

Factor: \(-12a^5b + a^3b^3 + ab^5\)

\(-ab\left(3a^2 - b^2\right)\left(4a^2 + b^2\right)\)