A plumber charges a $40 service fee plus $25.00 per hour. how many hours did the plumber work if he charged a total of $165.00?

5 hours

Step-by-step explanation:

y = mx + b

25 per hour = mx = 25x

40 service fee = y intercept = + b = + 40

The equation is:

y = 25x + 40

To solve this, first subtract 40 from 165.

165 - 40 = 125

Now, divide 125 by 25 to find out how many hours he worked.

25 goes into 100 4 times.

100 + 25 = 125

25 goes into 125 five times.

125/25 = 5

He worked 5 hours.