center of massplease help
posted by Anonymous .
The CM of an empty 1170 kg car is 2.50 m behind the front of the car. How far from the front of the car will the CM be when two people sit in the front seat 2.8 m from the front of the car, and three people sit in the back seat 3.90 m from the front? Assume that each person has a mass of 73 kg.

CM*totalmass=CM1*m1+CM2*m1+CM2*m3
CM(1170+2*73+2*73)=1170*2.5+2*73*2.8+2.&3*3.9
solve for CM. 
thank you so much!