SOLUTION: Can you help me make my a new quadratic function word problem and give the solution?

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Question 1047772: Can you help me make my a new quadratic function word problem and give the solution?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Example :
The length of a rectangle is three more than twice the width. Determine the dimensions that will give a total area of 27m%5E2.

Solution:
First we need to draw a picture to visualize the problem. Since the length is 3 more that twice the width, we will have l=2w%2B3. So we have the following picture:

Now, since both parts of this question deal with the area of this rectangle, lets begin by generating a function for the area.

Since A=wl we have:
A=w%282w%2B3%29
A=2w%5E2%2B3w
First, we want to know what dimensions make an area of 27m%5E2. Thus, we can insert 27 for +A into our function and solve for w.
We have:
27=2w%5E2%2B3w
2w%5E2%2B3w-27=0.........factor completely
2w%5E2%2B9w-6w-27=0
%282w%5E2-6w%29%2B%289w-27%29=0
2w%28w-3%29%2B9%28w-3%29=0
%28w-3%29+%282w%2B9%29+=+0
solutions:
if %28w-3%29++=+0->w=3
if %282w%2B9%29+=+0+->w=-9%2F2
So, since w represents the width of a rectangle we must omit the negative value.Therefore, we have w=3. Plugging that value into l=2w%2B3 we get l=2%2A3%2B3->l=9
Therefore, the dimensions that give the rectangle an area of 27m%5E2 are 9m by 3m.