Answer:
a. 
b. 
Step-by-step explanation:
First, we need tot find a general expression for the amount of caffeine remaining in the body after certain time. As the problem states that every hour x percent of caffeine leaves the body, we must substract that percentage from the initial quantity of caffeine, by each hour passing. That expression would be:

Then, to find the amount of caffeine metabolized per hour, we need to differentiate the previous equation. Following the differentiation rules we get:

The rate is negative as it represents the amount of caffeine leaving the body at certain time.
Answer:
440
Explanation:
If 50% of the total gum balls are red which is 220, then the other 50% is 220.
28.27 is the area bc i had this as an example before lol
18 x 3 = 54. So the correct answer is D. 54 pounds.
3/4x - 16 = 28
+16 +16
3/4x = 44
*3/4 *3/4
x = 176/3