ANSWER
5 hours
EXPLANATION
Let h be the number of hours per labor. We know that they charge $48 per hour of labor, so for h hours, the cost is $48h.
In this case, the total cost of parts was $265 and that plus the h hours of labor resulted in a bill for a total of $505,
[tex]505=265+48h[/tex]We have to solve this equation for h. First, subtract 265 from both sides,
[tex]\begin{gathered} 505-265=265-265+48h \\ \\ 240=48h \end{gathered}[/tex]And then divide both sides by 48,
[tex]\begin{gathered} \frac{240}{48}=\frac{48h}{48} \\ \\ 5=h \end{gathered}[/tex]Hence, you were charged for 5 hours of labor.
