College mathematics

Question

John is working 2 jobs. Job 1 pays $15/h, job 2 pays $17/h. One week he works in the second job 3 hours less than twice as many hours as in job 1. His total income for that week is $929. How many hours did he work at the 2nd job?

Answer 1

y=-3+2x

15x+17y=929

15x+34x-51=929

49x= 980

x= 980/49= 20 hours at 1st job

37 at 2nd

15(20)+17(37)=300+629=929