The cost of servicing a car is partly constant and partly varies with the time it takes to do the work.it cost 2500 for 2 hours services and 4000 for 3 1\2 hours service. find the formula connecting cost C and time T T when C =7500
Cost = mt + c
when t = 2, cost = 2500
2m + c = 2500
when t = 3.5, cost = 4000
3.5t + c = 4000
subtract them to get
1.5t = 1500
solve for t and take it from there