00:01
Okay, we know bracket of a and b is the largest common divisor of both a and b.
00:16
So for any d that divides a, and d divides b, we know d also divides b.
00:36
This is just a, and d divides a plus b.
00:44
This is a very, very easy conclusion, right? once d divides a and d divides b, d must also divide a plus b.
00:55
That means this one divides a plus b, because for any common divisor of both a and b, it is also a common divisor of b and a plus b.
01:17
That means the largest common divisor of a and b can divide the largest common divisor of a and b.
01:30
A plus a, b, and d...