Worked hours

Question

Two mechanics worked on a car. The first mechanic charged $65 per hour, the second mechanic charged $80 per hour. The mechanics worked for a combined total of 25 hours, and together they charged a total of $1850. How long did each mechanic work?

Answer 1

x=# of hours

65x+80(25-x)=1850

65x+2000-80x=1850

-15x+2000=1850

-15x=-2000+1850

-15x=-150

x=-150/-15

x=10 hours

10 hours at $65 per hour and 15 hours at $80 per hour

check: 10*65+15*80=$650+$1200=$1850