A water company charges $20 for service and $2.75 for every thousand gallons of water used in month. Construct a linear model to represent the water bill; how much would you be charged if you used 13-thousand gallons of water this month? Round your answer to the nearest cent. Do not include units with your answer.
help

Let

x > thousand. gallons of water used in month

y > the total charge in dollars

we know that

The linear equation in slope intercept form is equal to

where

m is the rate or slope

b is the y-intercept or initial value

In this problem we have that

substitute

The linear equation that represent this situation is

so

If you used 14-thousand. gallons of water this month

then

x=14

substitute the value of x in the linear equation and solve for y

y=58.50