How do I solve for c

Apatient is given 50 mg dose of medicine the medicines effectiveness decreases every hour at a constant rate of 40% what is the exponential decay function that models this scenario how much medicine will be left in the patients system after 2 hours

Asquare parking lot has 6,400 square meters what is the length in meters

Plot the points (0,6), (3,15.8), and (9.5,0) using the graphing tool, and find the function