We can use distribution property to multiply the polynomial by the monomial.
$$ \begin{aligned} \color{blue}{-4x} \cdot \left( -8x-9 \right) &= \color{blue}{-4x} \cdot \left( -8x\right) + \color{blue}{-4x} \cdot \left( -9\right) = \\ &= 32x^2+36x \end{aligned} $$