Write a system of equations to describe the situation below, solve using substitution, and fill in the blanks. Mr. Mason, the owner of two car dealerships in Fairfax, is holding a contest to see which one can sell the most cars. Fairfax Cars has already sold 19 cars, and Mason's Autos has sold 18 cars. Going forward, the salespeople at Fairfax Cars think they can sell 1 car per day, whereas the salespeople at Mason's Autos are aiming for sales of 2 cars per day. If the salespeople's predictions are accurate, it won't be long before the two dealerships are tied. How many cars will each lot have sold? How long will that take?