Question

If a person walks at 4 mph, he covers a certain distance. If he walks at
9 mph, he covers 7.5 miles more. How much distance did he actually cover?
Reiny
let the time be t hours
at 4 mph, the person covers 4t miles
at 9 mph, the person covers 9t miles
9t - 4t = 7.5

carry on ...