p 73 # 12, 13 (My own view is that none of these arguments qualify as a proof. Whatever further defects they may have, they all beg the question. Rephrasing the thing to be proved, and THEN asserting that it is obvious, is no way to prove it.)
14, 16, 20, 25, 32, 46, 47. 

Read 53, but don't work it. Instead, give YET ANOTHER way to express uniqueness.
58, 65. For 65, Hint: Consider the fact that 2^{(log(3))/(log(2))}=3. Can this be modified to give 2^(something)=irrational? Do we know that log 3 divided by log 2 is irrational? 

Incidentally, that ratio is the same, no matter which base is used for logarithms. But just to be definite, unless specified otherwise, log shall denote natural log, or log base e. 

p 85 # 1, 7, 14, 17, 20, 28. Read 30. It took a major book to sort out the paradox embodied in those innocent looking few words. It is scarily easy to talk about reason and logic in a way that sounds reasonable, but is unsound when one gets to the bottom of it.