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**samtheman17** The rate of change of *q* with respect to time (in days) is *dq*/*dt*= 60 . The rate of change of revenue over time, *dR*/*dt*, is to be found when *q*= **480** . Differentiate both sides of the equation *R*= 120 q- q^2/240 with respect to t to get *dR*/*dt*= ** 120 ** *dq*/*dt* − 1/ ** 120 ** *q* *dq*/*dt*.

Now substitute the known values for *q* and *dq*/*dt* to get *dR*/*dt*= ___*___ - 1/ ___ * ___ * ___

Thus the revenue is increasing at the rate of $_____ per day

i dont know how to sub in the answers to get the correct answer!