How is the following operation justified? Specifically, what happens to the $4^n$ in the numerator. I tried looking online but could not determine how this was justified. Thanks.
$$\dfrac{(-3)^{n-1}}{4^n}= \dfrac{1}{4}\cdot \left(-\dfrac{3}{4}\right)^{n-1}$$
The $4^n$ is in the denominator.
It becomes $4\cdot 4^{n-1}$
The $4^{n-1}$ is then combined with the $(-3)^{n-1}$ in the numerator.