SOLUTION: The problem involves constructing a rectangular planter. The area of the bottom needs to be 90 ft sq. Length of planter needs to be three feet longer than twice its width. What

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Question 933994: The problem involves constructing a rectangular planter.
The area of the bottom needs to be 90 ft sq.
Length of planter needs to be three feet longer than twice its width.
What should the dimensions of the bottom of the planter be?
This is an 8th grade algebra problem.
We know the given answer is 6 ft by 15 ft.
How do we factor this? We are trying to figure the structure of solving the problem.

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
For a rectangle,
A=L%2AW
L%2AW=90
Length of planter needs to be three feet longer than twice its width
L=3%2B2W
Substitute into the area equation,
%283%2B2W%29W=90
2W%5E2%2B3W=90
2W%5E2%2B3W-90=0
%28W-6%29%282W%2B15%29=0
Only the positive solution makes sense here.
W-6=0
W=6
Then,
L=3%2B2%286%29
L=3%2B12
L=15