A bakery is thinking of purchasing a small delivery truck that has a first cost of $18,000 and its to be kept in service for 6 years, at which time the salvage value is expected to be $2500. Maintenance and operating costs are estimated at $2500 the first year and will increase at a rate of $200 per year. Determine the present worth of this vehicle, using an interest rate of 12 percent.

My attempt:

Finding the regular annuity for such an arithmetic series,

Finding the present worth of maintenance costs given such an annuity, (NOTE: A here is A'' found previously)

Finding the present worth of the future salvage value,

Thus the overall present worth of the vehicle is,

Is this correct?