How to do the last question on page 67 of the fourth grade math classroom exercise book?
Suppose that car B has traveled for x hours, and car A leaves two hours earlier than car B, then car A has traveled for X+2 hours, and the distance is equal to the speed multiplied by the time. Car A traveled 65(X+2) kilometers and car B traveled 85X kilometers. If the vehicle B passes10km of the vehicle A, it means that the vehicle B has traveled10km, 85x-65 (x+).