Answer:
a) 
b) 
c) term number 17 is the one that gives a value of 40
Step-by-step explanation:
a)
The sequence seems to be arithmetic, and with common difference d = 3.
Notice that when you add 3 units to the first term (-80, you get :
-8 + 3 = -5
and then -5 + 3 = -2 which is the third term.
Then, we can use the general form for the nth term of an arithmetic sequence to find its simplified form:

That in our case would give:

b)
Therefore, the term number 20 can be calculated from it:

c) in order to find which term renders 20, we use the general form we found in step a):

so term number 17 is the one that renders a value of 40
The total price of the cinnamon with tax is $4.61
Step-by-step explanation:
Cost of the cinnamon= $4.25
Tax = 8.625%
Total price of the cinnamon= 4.25 + (8.625% of 4.25)
= 4.25 + (8.625/100) 4.25
= 4.25 + (0.36)
= $4.61
The total price of the cinnamon with tax is $4.61
Contour integration is a method of evaluating certain integrals along paths in the complex plane.