Question

8. The city's water company charges a fee of $20
a month in additional to a $0.25
per gallon used.

Use the function c=0.25x+20
, where c
is the total cost per month for water services and x
is gallons used, which following points on the graph accurately represent a monthly usage of 1,200
gallons?

(1 point)
Responses

(1,200 , 320)
(1,200 , 320)

(320 , 1200)
(320 , 1200)

(1,200 , -180)
(1,200 , -180)

(1,200 , 300)

Answer 1

To determine the total cost \( c \) for using 1,200 gallons of water, we can substitute \( x = 1200 \) into the function \( c = 0.25x + 20 \).

Calculating \( c \):

\[
c = 0.25(1200) + 20
\]
\[
c = 300 + 20
\]
\[
c = 320
\]

The point that accurately represents a monthly usage of 1,200 gallons is \( (1200, 320) \).

Now, let's analyze the given options:

1. \( (1200, 320) \) - This is the correct representation.
2. \( (320, 1200) \) - Incorrect, as the coordinates are reversed.
3. \( (1200, -180) \) - Incorrect, as the cost cannot be negative.
4. \( (1200, 300) \) - Incorrect, as the cost is 320, not 300.

The correct response is:

**(1200, 320)**.