August 31, 2016, 2.0

1.1
Difficult: Remembering that the Division Algorithm requires b > 0.
Reflective: It seems Corollary 1.2 is an easier-to-remember version of the Division Algorithm.  I like it!

1.2
Difficult: It looks hard to come up with a back-substitution in the Euclidean Algorithm to show the gcd as a linear combination of the two integers.
Reflective: The greatest common divisor is a linear combination of the two numbers it divides.  Does that mean, consequently, that a number cannot be a linear combination of two numbers if it is not a common divisor?

1.3
Difficult: I'm having a hard time understanding Theorem 1.8
Reflective: Why is the Fundamental Theorem of Arithmetic important?  It just seems to be a tautology to me.