Answer: the first mechanic charged $105 per hour and the second mechanic charged $95 per hour.
Step-by-step explanation:
Let x represent the the rate charged per hour by the first mechanic.
Let y represent the the rate charged per hour by the second mechanic.
The first mechanic worked for 10 hours, and the second mechanic worked for 5 hours. Together they charged a total of $1525. This means that
10x + 5y = 1525- - - - - - - - -1
if the sum of the two rates was $200 per hour, it means that
x + y = 200
Substituting x = 200 - y into equation 1, it becomes
10(200 - y) + 5y = 1525
2000 - 10y + 5y = 1525
- 10y + 5y = 1525 - 2000
- 5y = - 475
y = - 475/ - 5
y = 95
x = 200 - y = 200 - 95
x = 105