He percent of concentration of a certain drug in the bloodstream x hours after the drug is administered is given by K(x)equalsStartFraction 5 x Over x squared plus 9 EndFraction . a. Find the time at which the concentration is a maximum. b. Find the maximum concentration.

An initial investment of $100 is now valued at $150. the annual interest rate is 5%, compounded continuously. the equation 100e0.05t = 150 represents the situation, where t is the number of years the money has been invested. about how long has the money been invested? use your calculator and round to the nearest whole number. years