Hello, I'm having some trouble with the following question, and have not been able to solve it despite excessive attempts:

Find all ordered pairs of integers (x,y) such that $\displaystyle x^2+2x+18=y^2 $

I tried square-rooting both sides so that the equation could be solved for y, but didn't have any luck. I also thought about using the "completing the square" method, but am not sure on how to use it in this case. I would greatly appreciate any help.

Thanks!