On a drive from one city to? another, victor averaged 39 mph. if he had been able to average 72 ?mph, he would have reached his destination 11 hrs earlier. what is the driving distance between one city and the? other?

Respuesta :

Let the unknown distance be xmiles
x/39-x/72=11hr
72x-39x/2808=11hr
33x/2808=11
33x= 30888
x=936miles
U can substitue back to check
at speed of 72mph, he would need 936/72=13hrs
at speed of 39mph, he would need 936/39=24hr
the difference is 24-13=11