A $25,000 vehicle depreciates $2000 a year as it ages. Repair costs are $1500 per year.

(a) Write formulas for each of the two linear functions at time t, value, V (t), and repair costs to date, C(t). Graph them. 

(b) One strategy is to replace a vehicle when the total cost of repairs is equal to the current value. Find this time. 

(c) Another strategy is to replace the vehicle when the value of the vehicle is some percent of the original value. Find the time when the value is 6%.