calculus question:

please, I need some help with this question answer.

thank you so much in advance.

71(7)

The effect E of a drug on a human patient is a function of both the amount z (in milligrams) of the drug administered and the amount of time t (in hours) that has passed since the drug was administered. For a particular drug, the function that relates these quantities is E(x, t) - 16.5x1.20 e -0.04t Round all answers to 2 decimal places. a. Find the effect that 150 mg of the drug has on a patient 3 hours after it has been administered. E(150, 3) = b. Find the change in the effect of the drug on the patient if the dosage had been 140 mg rather than 150. Hint: Find the difference between E(140, 3) and your answer in part a. c. Find the change in the effect of the drug 4 hours after 150 mg has been administered. Hint: Find the difference between E(150, 4) and your answer in part a