Page 25 - Numbertheory
P. 25
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gcd(a, b ) ()
gcd(45, 75) :
gcd(45, 75) = gcd(45, 30)
= gcd(30, 15)
= gcd(15,15)
= 15
.( )
:
gcd(a1,a2, ... , an ) = gcd(a1,a2 , ... ,an−2, gcd(an−1,an ) )
. gcd(35, 45, 75) ()
. gcd(45, 75) = 15 ( )
gcd(35, 45,75) = gcd(35,15)
35 = 2 ×15 + 5
15 = 3×5 + 0
. gcd(35, 45, 75) = gcd(35, 15) = 5
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