SOLUTION: John has 1424 meters of fencing and wants to enclose a rectangular plot that borders on a lake. If he does not fence along the lake, what is the largest area that can be enclosed?

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Question 1098344: John has 1424 meters of fencing and wants to enclose a rectangular plot that borders on a lake. If he does not fence along the lake, what is the largest area that can be enclosed?
My work:
I set up two equations, 1.) and 2.)
1.) A=LW
2.) 2W%2BL=1424
Using 2W%2BL=1424, I solved for L
L=-2W%2B1424
Using A=LW I plug in the L from the above equation
A=%28-2W%2B1424%29W
A=-2W%5E2%2B1424W
Then I found the vertex using -b%2F2a
%28-1424%2F2%28-2%29%29+=356
Using 356 I plug it into the equation A=-2W%5E2%2B1424W
A=-2%28356%29%5E2%2B1424%28356%29
This gives me the largest area = 253,472 meters squared m%5E2 as my final answer.
I'm just wondering if this is ok or totally off

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
It is   PERFECTLY RIGHT  and   PERFECTLY CORRECT.


As my present/my gift to you,  consider these lessons in this site
    - HOW TO complete the square to find the minimum/maximum of a quadratic function
    - Briefly on finding the minimum/maximum of a quadratic function
    - HOW TO complete the square to find the vertex of a parabola
    - Briefly on finding the vertex of a parabola
    - A rectangle with a given perimeter which has the maximal area is a square
    - A farmer planning to fence a rectangular garden to enclose the maximal area
    - A farmer planning to fence a rectangular area along the river to enclose the maximal area (*)
    - A rancher planning to fence two adjacent rectangular corrals to enclose the maximal area
    - Using quadratic functions to solve problems on maximizing revenue/profit
    - OVERVIEW of lessons on finding the maximum/minimum of a quadratic function

The lesson marked (*) in the list has very close/similar problem.


Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic "Finding minimum/maximum of quadratic functions".


Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.