Two mechanics worked on a car. the first mechanic worked for
20
hours, and the second mechanic worked for
15
hours. together they charged a total of
$2100
. what was the rate charged per hour by each mechanic if the sum of the two rates was
$125
per hour?

Write a system of equations:

x + y = 125

20x + 15y = 2100

Solving:

x = 125 - y

20(125 - y) + 15y = 2100
2500 - 20y + 15y = 2100
2500 - 5y = 2100
-5y = 2100 - 2500
-5y = -400
y=80

x + 80 = 125
x = 125 - 80
x = 45

The first charges 45$ per hour and the second charges 80$ per hour