SOLUTION: whats the answer to this. the sum of the squares of two consecutive odd integers is 173. find the integers

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Question 230534: whats the answer to this.
the sum of the squares of two consecutive odd integers is 173. find the integers

Found 2 solutions by jsmallt9, Alan3354:
Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
First of all, the information you have provided is incorrect. The problem you have given has no solutions. This is because:
  1. The square of any odd number is also odd.
  2. Adding any two odd numbers always results in an even number.
  3. 173 is odd
  4. So it is impossible for the sum of two odd numbers to add up to another odd number.

So either the 173 should be even or the two (consecutive odd numbers) should be odd. I will go as far as I can with the incorrect information and hope that it will help you figure out how to do the correct problem.

Consecutive odd integers are 2 apart from each other. (This may seem wrong initially but think about some odd integers and it will become clear that they are 2 apart from each other.) Now we can write expressions for our two consecutive odd integers:
Let x = the smaller odd integer
then
  • x%5E2 = the square of the smaller odd integer
  • (x+2) = the next (larger) odd integer
  • %28x%2B2%29%5E2 = the square of the second odd integer
  • x%5E2+%2B+%28x%2B2%29%5E2 = the sum of the squares of the two consecutive odd integers.

From the information in the problem we know that:
x%5E2+%2B+%28x%2B2%29%5E2+=+173
This is a quadratic equation (because of the x%5E2 terms) so we will solve this by simplifying:
x%5E2+%2B+x%5E2+%2B+4x+%2B+4+=+173
2x%5E2+%2B4x+%2B+4+=+173
... getting one side equal to zero...:
2x%5E2+%2B4x+%2B+%28-169%29+=+0
... and then factoring (or using the quadratic formula).

And here is where we get stuck because the problem you've given is incorrect. This does not factor and the quadratic formula comes up with irrational, not odd, answers. Once you correct the problem, I hope the above will be a help to you in solving it.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
the sum of the squares of two consecutive odd integers is 173. find the integers
------------
This is not possible.
The square of an odd number is an odd number.
Any 2 odd numbers add to an even number, so it can't be 173.
Any 2 even numbers also add to an even number, so there are no integers that do this.
------------------
x^2 + (x+2)^2 = 173
2x^2 + 4x + 4 = 173
2x^2 + 4x - 169 = 0
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 2x%5E2%2B4x%2B-169+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%284%29%5E2-4%2A2%2A-169=1368.

Discriminant d=1368 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-4%2B-sqrt%28+1368+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%284%29%2Bsqrt%28+1368+%29%29%2F2%5C2+=+8.24662100445346
x%5B2%5D+=+%28-%284%29-sqrt%28+1368+%29%29%2F2%5C2+=+-10.2466210044535

Quadratic expression 2x%5E2%2B4x%2B-169 can be factored:
2x%5E2%2B4x%2B-169+=+%28x-8.24662100445346%29%2A%28x--10.2466210044535%29
Again, the answer is: 8.24662100445346, -10.2466210044535. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B4%2Ax%2B-169+%29