Problem 1E: Show that 15 is an inverse of 7 modulo 26 Problem 2E: Show that 937 is an inverse of 13 modulo 2436. Problem 3E: By inspection (as discussed prior to Example 1), find an inverse of 4 modulo 9. Problem 4E: By inspection (as discussed prior to Example 1), find an inverse of 2 modulo 17. Problem 5E: Find an inverse of a modulo m for each of these pairs of relatively prime integers using the method... Problem 6E: Find an inverse of a modulo m for each of these pairs of relatively prime integers using the method... Problem 7E: Show that if a and m are relatively prime positive integers, then the inverse of a modulo m is... Problem 8E: Show that an inverse of a modulo m, where a is an integer and m2 is a positive integer, does not... Problem 9E: Solve the congruence 4x5(mod9) using the inverse of 4 modulo 9 found in part (a) of Exercise 5. Problem 10E: Solve the congruence 2x7(mod17) using the inverse of 2 modulo 17 found in part (a) of Exercise 6. Problem 11E: Solve each of these congruences using the modular inverses found in parts and (b),(c), and(d) of... Problem 12E: Solve each of these congruences using the modular inverses found in parts and (b),(c), and(d) of... Problem 13E: Find the solutions of the congruence 15x2+19x=5(mod11) . [Hint: Show the congruence is equivalent to... Problem 14E: Find the solutions of the congruence 12x2+25x10(mod11) . [Hint: Show the congruence is equivalent to... Problem 15E: Show that if m is an integer greater than 1 and acbc(modm) , then ab (modm/gcd(c,m)) . Problem 16E: a) Show that the positive integers less than 11, except 1 and 10, can be split into pairs of... Problem 17E: Show that if p is prime, the only solutions of x21(modp) are integers x such that x1(modp) or... Problem 18E: a) Generalize the result in part (a) of Exercise 196; that is, show that if p is a prime, the... Problem 19E: This exercise outline a proof of Fermat’s little theorem Suppose that a is not divisible by the... Problem 20E: Use the construction the proof of the Chinese remainder theorem to find all solutions to the system... Problem 21E: Use the construction the proof of the Chinese remainder theorem to find all solutions to the system... Problem 22E: Solve the system of congruence x3(mod6) and x4(mod7) using the method of back substitution. Problem 23E: Solve the system of congruence in Exercise 20 using the method of back substitution. Problem 24E Problem 25E: Write out in pseudocode an algorithm for solving a simultaneous system of linear congruences based... Problem 26E: Find all solutions, if any, to the system of congruences x5(mod6),x2(mod10) , and x8(mod15) . Problem 27E: Find all solutions, if any, to the system of congruences x7(mod9),x4(mod12) , and x16(mod21) . Problem 28E: Use the Chinese remainder theorem to show that an integer a, with 0am=m1m2...mn , where the positive... Problem 29E Problem 30E: Complete the proof of the Chinese remainder theorem by showing that the simultaneous solution of a... Problem 31E: Which integers leave a remainder of 1 when divided by 2 and also leave a remainder of 1 when divided... Problem 32E: Which integers divisible by 5 but leave a remainder of 1 when divided by 3? Problem 33E: Use Fermat’s little theorem to find 7121 mod 13. Problem 34E: Use Fermat’s little theorem to find 231002 mod 41. Problem 35E: Use Fermat’s little theorem to show that if p is prime and pa , then ap2 is and inverse of a modulo... Problem 36E: Use Exercise 35 to find an inverse of 5 modulo 41. Problem 37E: a) Show that 23401(mod11) by Fermat's little theorem and noting that 2340=(210)34 . b) Show that... Problem 38E: a) Use Fermat’s little theorem to compute 3302 mod 5,3302 mod 7, and 3302 mod 11. b) Use your... Problem 39E: a) Use Fermat’s little theorem to compute 52003 mod 7,52003 mod 11, and 52003 mod 13. b) Use your... Problem 40E: Show with the help of Fermat’s little theorem that if n is positive integer, then 42 divides n7-n . Problem 41E: Show that if p is and odd prime, then every divisor of the Mersenne number 2p-1 is of the form 2kp+1... Problem 42E: Use Exercise 41 to determine whether M13=213-18191 and M23=223-1=8,388,607 are prime. Problem 43E: Use Exercise 41 to deter mine whether M11=2111=2047 and M17=2171131,071 are prime. Let n be a... Problem 44E: Show that if n is prime and b is a positive integer with nb , then n passes Miller’s to the base b. Problem 45E: Show that 2047 is a strong pseudoprime to the base 2 by showing that it passes MIiller’s test to the... Problem 46E: Show that 1729 is a Carmichael number. Problem 47E: Show that 2821 is a Carmichael number. Problem 48E: Show that if n=p1p2pk , where p1,p2,,pk are distinct primes that satisfy Pj1n1 for j=1,2,,k , then n... Problem 49E: Use Exercise 48 to show that every integer of the form (6m+1)(12m+1)(18m+1) , where m is a positive... Problem 50E: Find the nonnegative integer a less than 28 represented by each these pair, where each pair... Problem 51E: Express each nonnegative integer a less than 15 a pair (a mod 3, a mod 5). Problem 52E: Explain how to use the pairs found in Exercise 51 to add 4 and 7. Problem 53E: Solve the system of congruences that arises in Example 8. Problem 54E: Show that 2 is a primitive root of 19. Problem 55E: Find the discrete logarithms of 5 and 6 to the base 2 modulo 19. Problem 56E: Let p be and odd prime and r a primitive root of p. Show that if a and b are positive integers in Zp... Problem 57E: Write out a table of discrete logarithms modulo 17 with respect to the primitive root3. If m is a... Problem 58E: Which integers are quadratic residues of 11? Problem 59E: Show that if p is an odd prime and a is an integer not divisible by p, then congruence x2=(modp) has... Problem 60E: Show that if p is and odd prime, then there are exactly (p1)/2 quadratic residues of p among the... Problem 61E: Show that if p is and odd prime and a and b are integers with ab(modp) , then (ap=bp) Problem 62E: Prove Euler’s criterion, which states that if p is an odd prime and a is a positive integer not... Problem 63E Problem 64E: Show that if p is an odd prime, then -1 is a quadratic residue of p if p=1(mod4) , and -1 is not a... Problem 65E: Find all solutions of the congruence x2=29(mod35) . [Hint: Find the solutions of this congruence... Problem 66E Problem 67E format_list_bulleted