Question 1205921
A plumber earns $15 per hour more than his apprentice.
 In each 40-hour week, their combined earnings are $2200.
 What is the hourly rate for each? 
:
let a = the apprentice's hourly wage
then
(a+15) = the plumbers wage
:
40a + 40(a+15) = 2200
40a + 40a + 600 - 2200
80a = 2200 - 600
80a = 1600
a = 1600/80
a = $20 an hour for the apprentice
I'll let you find the plumber's wage, check it out in the total wage equation