A truck is to be driven 140 km at a constant speed of x km/hour. Assume that gasoline costs 230 cents / litre and is consumed at the rate of 8 + x2/90 litres/hour. The driver is paid 2100 cents/hour. Answer the following questions. Note: The last question requires a numerical answer which should be rounded to exactly one decimal place (so for example 47.0 could be a correct answer, but 47 and 47.03 could not be correct answers). Duration of the trip in hours as a function of x : Total cost of gasoline for the trip as a function of x : Total labour cost for the trip as a function of x : Total cost of the trip as a function of x: Speed which minimizes the cost of the trip, rounded to exactly one decimal place: x =Evaluate the integral Time left 2: (-3 . x7 + +5) dx. Evaluate the integral 5 - x +4 dx. XS Note: If you like, you can enter an answer in the form a/b - c/d + eff - g/h (or similar) which should save you some time you might otherwise have spent doing fraction arithmetic. Integrate of 5 - cos(x) . sin ?(x) dx. If you need to enter an expression of the form sin x (for example) into STACK, use the notation sin (x) 3. 17 Integrate dx. out of 8 X2 - 2)