
Hope you could get an idea from here.
Doubt clarification - use comment section.
So we know that there are 8 slices per large pizza (7), so a total of 56 slices
we would set up a proportion
5/8=x/56
8 times 7 gives you 56, and we would do that same thing to the 5 (multiply it by 7) to get 35?
so now we know that 35 out of 56 slices were eaten
56-35 is 21
so there are 21 slices left over
To evaluate

First, we input 0, for theta in the function to obtain:

This is an indeterminate form.
So, we apply L'Hopital's rule by differentiating the numerator and the denominator as follows:
The answer to your question is 7a.
Pretty sure it's A. (X times .5 equals Y)