Question

The city’s water company charges a fee of $20 a month in addition to a $0.25 per every gallon used. Using the function c=0.25x+20
𝑐
=
0.25
𝑥
+
20
, where c is the total cost per month for water services and x is gallons used, which of the following points on the graph accurately represents a monthly usage of 1,200 gallons?(1 point)
Responses

(320,1,200)
(
320
,
1
,
200
)
left parenthesis 320 comma 1,200 right parenthesis

(1,200,320)
(
1
,
200
,
320
)
left parenthesis 1,200 comma 320 right parenthesis

(1,200,−180)
(
1
,
200
,
−
180
)
left parenthesis 1,200 comma negative 180 right parenthesis

(1,200,300)

Answer 1

To determine the total cost for a monthly usage of 1,200 gallons using the given function \( c = 0.25x + 20 \), we substitute \( x = 1200 \) into the equation:

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

Calculating \( 0.25 \times 1200 \):

\[
0.25 \times 1200 = 300
\]

Now add the fixed fee:

\[
c = 300 + 20 = 320
\]

Thus, the total cost for using 1,200 gallons of water is $320. The point that accurately represents this monthly usage is \( (1,200, 320) \).

From the options you provided:
- \( (320, 1,200) \)
- \( (1,200, 320) \)
- \( (1,200, -180) \)
- \( (1,200, 300) \)

The correct answer is **(1,200, 320)**.