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.
The answer is rotation then translation. (:
Answer:
<u>The percent decrease of the microwave from the original price to the sale price is 24%</u>
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
Original price of a microwave = $ 75
Mark-up price of the microwave = $ 90
Sale price of the microwave = $ 57
2. What is the percent decrease from the original price to the sale price?
For answering this question we will use the Direct Rule of Three this way:
Price Percentage
75 100%
57 x
75x = 57 * 100
75x = 5,700
x = 5,700/75
x = 76
76 = 100 - 24
<u>The percent decrease of the microwave from the original price to the sale price is 24%</u>
(2,-2)(5,7)
7-(-2)= 9
5-2= 3
9/3= 3
slope = 3
(you could also calculate the slope by just counting up how many units it goes up/down when you pick a point from the x-axis and move left/right. basically counting the rise over run)