Question

Of all the rectangles with a perimeter of 100 feet, find the dimensions of the one with the largest area

Answer 1

P=2l+2w
100=2l+2w
divide both sides by 2
50=l+w

So what two numbers that have a sum of 50 have the largest product? 

25*25=625 which makes for a large area, the largest

answer=l=25 w=25