if tickets are sold for $50, then 600 tickets are expected to be sold. For each $1 reduction in price, an additional 20 tickets will be sold.
Write an equation that gives revenue R from ticket sales when the ticket prices are reduced by "x" dollars.
x = number of $1 reductions
price: 50-x
demand: 600+20x
R(x) = (50-x)(600+20x)