The mean age of a herd of cows is 7.9 years. a cow that is 0.5 years old is added to the herd. how does this cows age effect the mean

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

For each proportion find the unknown number x 1/5/8=×/15

Precalculus question, image attached.