Question

You just discovered that you have 100 feet of fencing and you have decided to make a rectangular garden. What is the largest area you can enclose using the materials you have? You must set up an equation and solve.

Answer 1

The area is:
A = x * y
The perimeter is:
P = 2x + 2y = 100
We clear y:
2y = 100-2x
y = 50-x
We write the area in terms of x:
A (x) = x * (50-x)
Rewriting:
A (x) = 50x-x ^ 2
Deriving:
A '(x) = 50-2x
We equal zero and clear x:
50-2x = 0
x = 50/2
x = 25
Then, the other dimension is given by:
y = 50-x
y = 50-25
y = 25
Therefore, the largest area is:
A = (25) * (25)
A = 625 feet ^ 2
Answer:
the largest area you can enclose using the materials you have is:
A = 625 feet ^ 2