Answer:
[tex]c = \dfrac{r+ ad}{b - 3}[/tex]
Step-by-step explanation:
[tex]\begin{array}{rcll}bc - ad& = & 3c + r &\\bc - 3c - ad & = & r & \text{Subtracted 3c from each side}\\bc - 3c & = & r + ad & \text{Added ad to each side}\\c(b - 3) & = & r + ad &\text{Removed the common factor} \\\mathbf{c} & = & \mathbf{\dfrac{r+ ad}{b - 3}} &\text{Divided each side by (b - 3)} \\\end{array}[/tex]
