Question

A person drove 30 miles per hour on a trip. If he had driven 40 miles per hour, he would have arrived 4 hours earlier. What was the distance the person drove?​

Answer 1

30 miles/hour * x hours= 40 miles/hour * (x-4) hours
Distribute the 40, so you get
30x=40x-160
Subtract 40x from both sides
-10x=-160
Divide both sides by -10
x=16
They drove 16 miles