Anika travelled 448 km by car to visit her mother for the holidays. She drove part of the way at 43 km/h and the rest of the way at 81 km/h. The whole trip took her 7 hours. How many hours did Anika travel at each speed?

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.