Hello,
What you want to do for this question is plug in numbers into the given equation.
1) as m is the variable for minutes, and you are given 60 minutes, replace m with 60 in the given equation.
h(m) = 20(60) + 2640
= 3840 feet
2) The most accurate way for this is using the given equation again.
This time, however, you are given the altitude, and are asked to solve the time.
In this case, you would substitute h(m), which is the variable for altitude, for 7260 feet as given in the question.
This equation would be 7260 = 20(m) + 2640
To solve for m, subtract 2640 on both sides to get
20(m) = 4620
Divide 20 on both sides to get
m = 231 minutes
Bonus: In this question you will be substituting 8000 feet for h(m), similar to what we did in the previous question.
This way, you get:
8000 = 20m + 2640
Subtract 2640 on both sides to get
5360 = 20m
Divide by 20 on both sides to get 268 MINUTES.
You want to solve for HOURS.
Therefore, divide 268 minutes by 60 to get the number of hours,
which is around 4.67 hours.
Hope this helped!