Ordered Pairs for x and y: How to Solve x2 + 2x + 18 = y2 with Integers?

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Homework Help Overview

The discussion revolves around finding all ordered pairs of integers (x, y) that satisfy the equation x² + 2x + 18 = y². Participants are exploring methods to approach this problem in the context of integer solutions.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss starting points, including square-rooting the equation and completing the square. There is mention of using trial and error to find integer solutions, and some participants question the validity of specific ordered pairs obtained.

Discussion Status

The discussion is ongoing, with participants providing initial attempts and questioning the correctness of results. There is a suggestion to complete the square, and some participants are seeking confirmation on their findings.

Contextual Notes

There is a focus on integer solutions, and participants are navigating through the implications of completing the square and the resulting equations. The nature of the problem suggests constraints related to the properties of integers.

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Homework Statement


Please find all ordered pairs of integers (x,y) such that x2 + 2x + 18 = y2

Homework Equations


x2 + 2x + 18 = y2

The Attempt at a Solution



Im not sure on how to begin. I tried square-rooting the expression, to solve for y, turning it into y = [tex]\sqrt{x + 2x + 18}[/tex]. I would greatly appreciate any help to get me started on this problem.

Thanks!
 
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spoc21 said:

Homework Statement


Please find all ordered pairs of integers (x,y) such that x2 + 2x + 18 = y2


Homework Equations


x2 + 2x + 18 = y2


The Attempt at a Solution



Im not sure on how to begin. I tried square-rooting the expression, to solve for y, turning it into y = [tex]\sqrt{x + 2x + 18}[/tex]. I would greatly appreciate any help to get me started on this problem.

Thanks!
It might be helpful to complete the square. Then you would have the difference of two squares being equal to -17.
 
Hey, thanks for the help.
So after this step, do we use trial and error to find the correct solution. I am getting one ordered pair, (9,9), and (-9,-7) after all the math(since x, and y can only be integers). I would really appreciate it if you could confirm this.
Thank you
 
Those ordered pairs you got aren't solutions. When you completed the square, what did you get for your equation?
 

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