Tickets for the historical review of ballroom dancing at the Portsmouth Music Hall cost $42 for the main-floor seats and $25 for the balcony seats. Let m represent the number of tickets sold for the main-floor seats and let b represent the number of tickets sold for the balcony seats. What is the algebraic expression for each of the following amounts?

(a) The cost in dollars of all the main-floor seats that were sold
(b) The total number of seats that were sold for the performance