SOLUTION: if two sides of a rectangle change so that the new area is double the original area,and one side is increased by 50%what is the percentage increse or decrease of the other side? ti

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Question 176987: if two sides of a rectangle change so that the new area is double the original area,and one side is increased by 50%what is the percentage increse or decrease of the other side? tis is my first math class in 17 years please show me the steps so i can see where i went wrong
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
if two sides of a rectangle change so that the new area is double the original area,and one side is increased by 50%what is the percentage increse or decrease of the other side? tis is my first math class in 17 years please show me the steps so i can see where i went wrong

Let the original area = A, the original length be L,
and the original width be W.
 
Then 

OLD AREA = (OLD LENGTH)(OLD WIDTH), so we have this
equation:

A+=+LW

The new area = 2A, because it was doubled.

The new length = L%2B%281%2F2%29L, because 50% or half of L 
was added to L.

We don't know what the width is multiplied by, so let's suppose
it was multiplied by some number k, making the new width kW

Then the new rectangle's area is given by:

NEW AREA = (NEW LENGTH)(NEW WIDTH)
      2A+=+%28L%2B%281%2F2%29L%29%28kW%29 
      2A+=+%281L+%2B+%281%2F2%29L%29%28kW%29
      2A+=+%281%261%2F2L%29%28kW%29
      2A+=+%283%2F2%29LkW
Clear of fractions by multiplying both sides by 2:
      2%2A2A=2%2A%283%2F2%29LkW
      4A+=cross%282%29%2A%283%2Fcross%282%29%29LkW
      4A+=+3LkW 
      
      
So we have the system of equations:

system%284A=3kLW%2C+A=LW%29

Now let's divide equals by equals:

%284A%29%2FA+=+%283kLW%29%2F%28LW%29

We cancel:

 

4=3k
4%2F3=k
1%261%2F3=k

So the width was multiplied by 1%261%2F3 so it was
increased by 1%2F3 or +matrix%281%2C2%2C33%261%2F3%2C%22%25%22%29

Edwin