Answer: Wheref(the) is the distance in kilometers and the input the is the time in hours
BC f(t) = -5t + 40
CD f(t) = 20. Or f(t)= -20(t/t)+40 OR f(t) = 0t + 20
DE f(t) = -5(t-2) + 40
Explanation:
The negative slope means that the distance is decreasing by 5 km/hr when there is movement. Between hours of 4 and 5, the slope is 0, but the distance remains constant at 20. All the options for CD are strange. But they describe the line segment in the graph.
Plug in the values of the hours to check.