Answer
$x=\dfrac{9b}{c}$
Work Step by Step
$c$ is a nonzero constant so both sides of the equation can be divided by $c$.
$$\begin{align*}
cx--4b+4b&=5b+4b &\text{Add $4b$ to both sides,}\\
cx&=9b &\text{Simplify.}\\
\frac{cx}{c}&=\frac{9b}{c} &\text{Divide $c$ to both sides.}\\
x&=\frac{9b}{c} &\text{Simplify.}
\end{align*}$$
