Finish these problems before you attend discussion this week. For #1
and #2, you should write the claim in logical notation (define the
universe and predicates), state the givens and goal, and show your
1. Prove that the sum of any rational number and any irrational number
2. Prove: For all integers a, b, and c, if a|b and a|c then a|(2b-3c).
3. What's wrong with the incorrect proof in #20 in the textbook on p.