Question

$4r^{-3} cdot 2r^{2}$

Explanation:

Step1: Multiply the coefficients

$4 \times 2 = 8$

Step2: Combine variable terms

$r^{-3} \times r^{2} = r^{-3+2} = r^{-1} = \frac{1}{r}$

Step3: Multiply results

$8 \times \frac{1}{r} = \frac{8}{r}$

Answer:

$\frac{8}{r}$