Answer: The mechanics spent about 8.5 hours working on the car
Step-by-step explanation: The total bill was $637, a portion of that being getting the parts which was $280. 637-280=357
357/42=8.5
We have
.
To find inverse function
we substitute x with
and vice-versa to get

Now solve for
. Note that I will use
instead.

So we find that
.
Hope this helps.
3/4=36/48 so 36 pieces can be made from the metal rod. Hope this helps!