Having trouble with this problem, please help!

Question

Two mechanics worked on a car. The first mechanic worked for 5

 hours, and the second mechanic worked for 15

 hours. Together they charged a total of $1725

. What was the rate charged per hour by each mechanic if the sum of the two rates was $145

 per hour?

Answer 1

15x -5x = 1725 - 725 = 1000

10x = 1000

x =$ 100 = 1st rate

145-100 = $45 = 2nd rate

1500+225 = 1725