PART A
To form the equation to represent total rent, we first need to establish the changing rate and the fixed cost. Changing rate is the fee for every one day the car is rented and fixed cost is the initial cost of the car rental.
To find the changing rate we divide the cost difference between two days by the difference of days
We have
$180 = 4 days
$ 325 = 9 days
The changing rate is

The table below shows the working out of the price for each day the car is rented. We work out that day 0 cost $63 which means this is the fixed cost
Hence, the equation of total cost is

, where

is the total cost and

is the number of days
PART B:
Using the function notation means we will use

instead of

, so the equation is

PART C:
To graph the function, we first need to set the scales on the x-axes and y-axes.
The scale on x-axes could go up in ones but must start from 0
The scale on y-axes, since it is much bigger values, we can go up in 50
We then plot on the graph for each pair of days and cost. The plots should give us a straight line graph
One example of the graph is shown below
A linear equation, as the exponent of x is one
Answer:
$48 - $4 = $44
Step-by-step explanation:
Explained above
distance = rate times time.
Here the distance covered by the first train is (70 km/hr)t (t=# of hours), and that by the second train is (85 km/hr)t.
Add these together and set the sum equal to 620 km:
70t + 85t = 620, or 155t = 620, or 4. It will take 4 hours for the distance between the two trains to increase to 620 km.
220 miles in 4 h = 55 mph multiply this by 5280 to get feet per hour then divide this by 60 to get ft/min