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 plumber charges $ __per hour.
The electrician charges $ ___per hour.