It will cost $73 perhour to rent a sailboat and $88 to rent a ski boat. how much more will it cost to rent a ski boat than a sailboat for four hours?

Well we want to find out how much more will it cost to rent a ski boat than a sailboat for four hours. 

All we have to do is Multiply 73 by 4 for the sailboat which gives you $292 

Now we do the same for the ski boat. $88 * 4 = $352 

So we now have to find out how much more it will cost for a ski boat than a sail boat. All we do is subtract 352 by 292 

352
-
292

$60 

Your answer is $60