Answer:
(a) ![gcd(20, 12)=4](https://tex.z-dn.net/?f=gcd%2820%2C%2012%29%3D4)
(b) ![gcd(100, 36)=4](https://tex.z-dn.net/?f=gcd%28100%2C%2036%29%3D4)
(c) ![gcd(496,207 )=1](https://tex.z-dn.net/?f=gcd%28496%2C207%20%29%3D1)
Step-by-step explanation:
The Euclidean algorithm is an efficient method for computing the greatest common divisor of two integers, without explicitly factoring the two integers.
The Euclidean algorithm solves the problem:
<em> Given integers </em>
<em>, find </em>
<em />
Here is an outline of the steps:
- Let
,
. - Given
, use the division algorithm to write
. - If
, stop and output
; this is the gcd of
. - If
, replace
by
. Go to step 2.
The division algorithm is an algorithm in which given 2 integers N and D, it computes their quotient Q and remainder R.
Let's say we have to divide N (dividend) by D (divisor). We will take the following steps:
Step 1: Subtract D from N repeatedly.
Step 2: The resulting number is known as the remainder R, and the number of times that D is subtracted is called the quotient Q.
(a) To find
we apply the Euclidean algorithm:
![20 = 12\cdot 1 + 8\\ 12 = 8\cdot 1 + 4\\ 8 = 4\cdot 2 + 0](https://tex.z-dn.net/?f=20%20%3D%2012%5Ccdot%201%20%2B%208%5C%5C%2012%20%3D%208%5Ccdot%201%20%2B%204%5C%5C%208%20%3D%204%5Ccdot%202%20%2B%200)
The process stops since we reached 0, and we obtain
.
(b) To find
we apply the Euclidean algorithm:
![100 = 36\cdot 2 + 28\\ 36 = 28\cdot1 + 8\\ 28 = 8\cdot 3 + 4\\ 8 = 4\cdot 2 + 0](https://tex.z-dn.net/?f=100%20%3D%2036%5Ccdot%202%20%2B%2028%5C%5C%2036%20%3D%2028%5Ccdot1%20%2B%208%5C%5C%2028%20%3D%208%5Ccdot%203%20%2B%204%5C%5C%208%20%3D%204%5Ccdot%202%20%2B%200)
The process stops since we reached 0, and we obtain
.
(c) To find
we apply the Euclidean algorithm:
![496 = 207\cdot 2 + 82\\ 207 = 82\cdot 2 + 43\\ 82 = 43\cdot 1 + 39\\ 43 = 39\cdot 1 + 4\\ 39 = 4\cdot 9 + 3\\ 4 = 3\cdot 1 + 1\\ 3 = 1\cdot 3 + 0](https://tex.z-dn.net/?f=496%20%3D%20207%5Ccdot%202%20%2B%2082%5C%5C%20207%20%3D%2082%5Ccdot%202%20%2B%2043%5C%5C%2082%20%3D%2043%5Ccdot%201%20%2B%2039%5C%5C%2043%20%3D%2039%5Ccdot%201%20%2B%204%5C%5C%2039%20%3D%204%5Ccdot%209%20%2B%203%5C%5C%204%20%3D%203%5Ccdot%201%20%2B%201%5C%5C%203%20%3D%201%5Ccdot%203%20%2B%200)
The process stops since we reached 0, and we obtain
.