Well, you already have the decay model, so just plug that in
Answer:
b
Step-by-step explanation:
Step by step subtract 20 from both sides and then subtract 20 from 9 to get -11
Answer: C=-11
Recall that for a home visit, the technician charges $50 regardless on the time spent in the repair.
So, to find out the rate, we should calculate the part that depends on the spent time, and the add 50. So for example, we know that the technician spents 1 hour. So, we multiply 1 times 25 and then add 50. So, 25*1 + 50 = 75, which is the rate for a 1-hour repair.
So, in general, if we know that the number of hours is x, we multiply x times 25 and then add 50. Then a table would like this:
x 25*x 25*x +50
1 25 75
2 50 100
3 75 125
4 100 150
Note that as the time increases by one hour, the fare increases by 25. This is an example of a direct variation, since as the independent variable increases (t
