Find the rate of change of totalrevenue, cost, and profit with respect to time. Assume thatR(x) andC(x) are in dollars.

R(x)=50x-0.5x^2

C(x)=5x+20

when x=25, dx/dt=20 units per day.

1. The rate of change of total revenue is $____ per day
2. The rate of change of total cost is $_____ per day
3. The rate of change of total profit is $____ per day