Ginger buys and sells/delivers roses. She buys roses for $5/dozen and sells them (delivered) for $15/dozen. She bought a bike ($450) for delivering the roses and a city license for $200. 1.Let d be the number of dozens of roses she buys/sells.
a) Write an equation relating her total expenses (e) to d (the number of roses).

b) Write an equation relating her total revenue (r) to d (the number of roses).