(New page: Category:MA453Spring2009Walther Chapter 0: 24, 25, 7, 14, 19, 21 Problem 24 *If p is prime and p divides a_1a_2...a_n, prove that p divides a_i for some i Problem 25 *Use the Gener...)
 
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Problem 21
 
Problem 21
 
*For every positive integer n, prove that a set with exactly n elements has exactly 2^n subsets (counting the empty set and the entire set)
 
*For every positive integer n, prove that a set with exactly n elements has exactly 2^n subsets (counting the empty set and the entire set)
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--[[User:Aifrank|Aifrank]] 13:56, 18 January 2009 (UTC)

Revision as of 08:56, 18 January 2009


Chapter 0: 24, 25, 7, 14, 19, 21

Problem 24

  • If p is prime and p divides a_1a_2...a_n, prove that p divides a_i for some i

Problem 25

  • Use the Generalized Euclid's Lemma to establish the uniqueness portion of the Fundamental Theorem of Arithmetic

Problem 7

  • Show that if a and b are positive integers, then ab = lcm(a, b) * gcd (a,b)

Problem 14

  • Show that 5n + 3 and 7n + 4 are relatively prime for all n

Problem 19

  • Prove that there are infinitely many primes. (hint: use ex. 18)

Problem 21

  • For every positive integer n, prove that a set with exactly n elements has exactly 2^n subsets (counting the empty set and the entire set)

--Aifrank 13:56, 18 January 2009 (UTC)

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