My book gave a theorem that stated that if a and a' both divide x and y, and that every g that divides x and y also divides a and a', then a and a' are associates.
My book gave a theorem that stated that if a and a' both divide x and y, and that every g that divides x and y also divides a and a', then a and a' are associates.
Can anyone prove this?
a and a' are both gcd's of x and y. What does this tell you?