Number Theory/Pythagorean Triples

[cathwelch]

Question:
If x, y, z is a primitive Pythagorean triple, prove that x+y and x-y are congruent modulo 8 to either 1 or 7.

 

[Deleted member 4993]

Question:
If x, y, z is a primitive Pythagorean triple, prove that x+y and x-y are congruent modulo 8 to either 1 or 7.

Please show us your work/thoughts, indicating exactly where you are stuck - so that we know where to begin to help you.

 

[cathwelch]

That is the problem; I am stuck on where to start. I was hoping you could lead me in the right direction? Thanks