A patient is given a 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 patient's system after two hours

exponential decay formula is
[tex]y = a(1 - r)^{x} \\ y = 50(1 - .40) ^{x} [/tex]
x= hours past
[tex]y = 50(1 - .40)^{2} \\ y = 18[/tex]
after 2 hours, there are 18 mg of medicine left