arnold has 24m of fencing to surround a garden, bounded on one side by the wall of his house. what are the dimensions of the largest rectangular garden that he can enclose?

how do i solve this question
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4 answers

A square is the largest area.

24/3 = ?
24/3 is 8
A square is the largest area for a given perimeter, if all sides are included. In this case, one side is not, so suppose the side parallel to the wall has length x, and the other sides have length y.

x+2y = 24

The area is

a = xy = (24-2y)y = 24y-2y^2

You know that this is just a parabola, with its vertex where y = 24/4 = 6.

So, y=6 and x=12, with area=72

An 8x8 square would only have area 64.
why did u multiply the whole thing by "y" for (24-2y)y ?