Question 301438
You can do a bunch of algebra to solve
{{{n^2 + (n+2)^2 = 20}}}
Or you can use a little 'common sense' and realize
- number squared are always positive
- 20 is a small number (between 4^2 and 5^2
- so use trial and error with even numbers
Try 2 and 4
2^2 = 4 
4^2 = 16
4+16= 20
done