Answer:
1. $ 272
2. 11 hours
Explanation:
Given the below equation;
[tex]C=28h+76[/tex]where C = the total cost
h = hours spent
1. If h = 7 hours, let's go ahead and find C;
[tex]\begin{gathered} C=28(7)+76 \\ =196+76 \\ \therefore C=272 \end{gathered}[/tex]So if it takes 7hours to fix the drain, the total cost will be $272.
2. If C = $384, let's go ahead and find h;
[tex]\begin{gathered} 384=28h+76 \\ 28h=384-76 \\ 28h=308 \\ h=\frac{308}{28} \\ \therefore h=11 \end{gathered}[/tex]So if the plumber charged $384 to fix the drain, it means that he'd spent 11 hours to fix the drain.