# How do you simplify (3d^-4)(5d^8)?

It is $\left(3 {d}^{-} 4\right) \left(5 {d}^{8}\right) = \left(3 \cdot 5\right) \cdot \left({d}^{-} 4 \cdot {d}^{8}\right) = 15 \cdot \left({d}^{8 - 4}\right) = 15 \cdot {d}^{4}$