Please help me , it’s my final exam ..

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.

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?

Which value would be a solution for x in the inequality 47-4x< 7