Question

A camera rental company charges a fixed amount plus a fee based on the number of days for which the camera is rented. The graph below shows the amount paid for a different number of days to rent the camera:

A graph titled Camera Rentals plots the Number of Days on the x axis and the Amount in dollars on the y axis. A straight line joins the ordered pairs 0, 40 and 4, 120.

What is the fixed amount charged?

$20
$30
$40
$80

Answer 1

Given:
x y
0 40
4 120

y = fixed amount + v(x)
y = 40 + v(0)
y = 40

y = 40 + v(x)
120 = 40 + v(4)
120 - 40 = v(4)
80 = v(4)
80/4 = v
20 = v

y = 40 + 20x

The fixed amount charged is 40.

The variable amount is 20 per day.

Answer 2

$40

Explanation:

We are given two points (0, 40) and (4, 120).

Now to find the equation which represents A graph titled Camera Rentals plots the Number of Days on the x axis and the Amount in dollars on the y axis.

To Find equation we will use two point slope form.

Formula:
`y-y_1=(y_2-y_1)/(x_2-x_1)(x-x_1)`

`(x_1,y_1)=(0,40)`

`(x_2,y_2)=(4,120)`

Substitute the values in the formula

`y-40=(120-40)/(4-0)(x-0)`

`y-40=(80)/(4)x`

`y-40=20x`

`y=20x+40`

The equation represents the situation :
`y=20x+40`

where x is the number of days

y is the Amount in dollars

Now we are supposed to find the fixed amount charged.

So, we need to substitute x i.e. number of days=0

So,
`y=20(0)+40`

`y=40`

Hence the fixed amount charged is $40.