please help show what excel formulas to use

C-Suppose that you have the option to buy the car with a 3 year car loan or lease the car during the same period of time. The 3 year lease option will require a $$,000 down payment and monthly payments of $350. If the salvage value of the new vehicle after 3 years is $5,000 and you can invest at a rate of return of 4%, what is your best option? (Ignore your old vehicle.) You want to buy a car by taking out a 3 year loan for $15,000 with a 7% interest rate