Question

In: Advanced Math

The least common multiple of nonzero integers a and b is the smallest positive integer m...

The least common multiple of nonzero integers a and b is the smallest positive integer m such that a|m and b|m. It is denoted [a, b], or sometimes [a, b] for short. Prove the following:

1) If a|k and b|k, then [a, b]|k.

2) If gcd(a, b) = 1, then [a, b] =ab

3) If c >0,then [ca, cb] =c·[a, b].

4) If a >0 and b >0,then [a, b] =ab / gcd(a, b).

Solutions

Expert Solution


Related Solutions

8.Let a and b be integers and d a positive integer. (a) Prove that if d...
8.Let a and b be integers and d a positive integer. (a) Prove that if d divides a and d divides b, then d divides both a + b and a − b. (b) Is the converse of the above true? If so, prove it. If not, give a specific example of a, b, d showing that the converse is false. 9. Let a, b, c, m, n be integers. Prove that if a divides each of b and c,...
An integer n is said to be Pythagorean if there exist two nonzero integers x and...
An integer n is said to be Pythagorean if there exist two nonzero integers x and y such that x2 + y2 = n2 . Present an O(n) time algorithm to check if a given integer n is Pythagorean or not. Assume that you can nd the square root of any number in O(1) time.
7. Let m be a fixed positive integer. (a) Prove that no two among the integers...
7. Let m be a fixed positive integer. (a) Prove that no two among the integers 0, 1, 2, . . . , m − 1 are congruent to each other modulo m. (b) Prove that every integer is congruent modulo m to one of 0, 1, 2, . . . , m − 1.
Write a Python program to find the smallest positive integer that is a perfect square and...
Write a Python program to find the smallest positive integer that is a perfect square and it contains exactly three different digits.
Let a and b be positive integers, and let d be their greatest common divisor. Prove...
Let a and b be positive integers, and let d be their greatest common divisor. Prove that there are infinitely many integers x and y such that ax+by = d. Next, given one particular solution x0 and y0 of this equation, show how to find all the solutions.
Write a C++ program to find least common multiple (LCM) of two, three and four integer...
Write a C++ program to find least common multiple (LCM) of two, three and four integer values. The integer values are entered from the keyboard and the outputs are printed to the console. The LCM of two, three and four integer values are computed using Prime factorization method. You have to use arrays to hold input values and use functions/methods to get data from the keyboard, display output to the console, calculate LCM using Prime factorization method. Your program should...
Write a C++ program to find least common multiple (LCM) of two, three and four integer...
Write a C++ program to find least common multiple (LCM) of two, three and four integer values. The integer values are entered from the keyboard and the outputs are printed to the console. The LCM of two, three and four integer values are computed using Prime factorization method. You have to use arrays to hold input values and use functions/methods to get data from the keyboard, display output to the console, calculate LCM using Prime factorization method. Your program should...
Find the smallest positive integer x that satisfies the system of congruences x ≡ 3 (mod...
Find the smallest positive integer x that satisfies the system of congruences x ≡ 3 (mod 5). x ≡ 5 (mod 7). x ≡ 7 (mod 11)
Show that if a, b are positive integers and d = hcf(a, b), then there are...
Show that if a, b are positive integers and d = hcf(a, b), then there are positive integers s, t such that d = sa − tb.
(3) Let m be a positive integer. (a) Prove that Z/mZ is a commutative ring. (b)...
(3) Let m be a positive integer. (a) Prove that Z/mZ is a commutative ring. (b) Prove that if m is composite, then Z/mZ is not a field. (4) Let m be an odd positive integer. Prove that every integer is congruent modulo m to exactly one element in the set of even integers {0, 2, 4, 6, , . . . , 2m− 2}
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT