Two mechanics worked on a car. The first mechanic charged $65 per hour, and the second mechanic charged $105 per hour. The mechanics worked for a combined total of 35 hours, and together they charged a total of $2875. How long did each mechanic work?

X=number of hours mechanic one worked

y=number of hours of mechanic 2

so

65x+105y=2875 and

x+y=35

solve, use elimination

multiply 2nd equation by - 65 and add to first one

-65x-65y=-2275

65x+105y=2875 +

0x+40y=600

40y=600

divide by 40 boht sides

y=15

sub back

x+y=35

x+15=35

x=20

the first one worked 20 hours

2nd one worked 15 hours

Devide 35 from 2875!