Please do a and b and explain

This is a decay problem,

The equation is written as start value x (1 - rate)^tike

Using the information given in the problem:

a) Total = 120(1-0.12)^Hours

b) Replace hours with 19 and solve:

Total = 120(1-0.12)^19

Total = 120(0.88)^19

Total = 10.57674 mg

Round the answer as needed.

i think it is c, not positive though

step-by-step explanation:

step-by-step explanation:

descending order means to order the polynomials from the term with the largest exponent to the term with the smallest exponent.  

therefore, the correct answer is d.