Question

The equation y = 55x + 85 describes the amount of money a plumber charges, where y is the total amount he charges and x is the number of hours he works. The table shows the total amount of money an electrician charges.

How much does each charge per hour?

Number of hours worked 1 2 4 7
Total amount charged 115 180 310 505

the plummer charges $___ per hour
the electrician charges $___ per hour

Answer 1

If you would like to know how much does each charge per hour, you can calculate this using the following steps:

x ... the number of hours
a plumber: y = 55x + 85 = 55 * 1 + 85 = 55 + 85 = $140 per hour
an electrician: y = $115 per hour

The correct result would be: the plumber charges $140 per hour and the electrician charges $115 per hour.