I drove to the beach at a rate of 40 miles per hour. If I had driven at a rate of 50 miles per hour instead, then I would have arrived 45 minutes later. How many miles did I drive?
+40 I assume that you mean 45 minutes earlier, if so then x is the miles you drove:
60x/40-45=60x/50,
3x/2-45=6x/5
3/10x-45=0
3/10x=45
3x=450
x=150
You drove 150 miles.
