Question with linear Diophantine equation

hi, sorry about that... posted wrong question x__x.

i would rename this thread but i don't think i can. i dont want to clutter the board so i will just post the problem here.

anyways... the problem that i would reaalllly appreciate some help on solving is this linear diophantine equation:

Suppose a, b not both zero. List all a, b for which ax + by = c have infinitely many positive integer

solutions (in terms of c). Explain.

thank you for taking the time to look :3

xoxox