Hi guys!

We gad a disscusiion on parabolas last week and I wasn;t able to understand it very well . Over the weekend,, our teacher gave us 35problems to solve, but I was stuck on these four numbers... How do you solve them? I don't think we have studied them yet in our class. Thanks!!

1) Find 2 numbers whose diff. is 20 and whose product is a minimum

2) What are the dimensios if the largest rectangle with a fixed perimetre "P"?

3) A student club on a collegre campus charges an annual membership dues of $40, less 20cents for each member over 60 (no. of ppl). How many members will give the clubthe most revenue from annual duies? What is the max. revenue??

4) A travel agency offers an organization an all inclulive tour for $8000 per person if not more than 100 persons join the tour. The cost per person will be reduced by $50 for each person in excess of 100. Find the largest possible gross sales revenue for the agency, and how many persons should join the tour? What's the cost per person so that the max revenue is achieved??