Page 48 - Numbertheory

@ @Hßìÿa@ö§aI@†a‡Èÿa@óî‹Åä@@

.1 = (−a) + a +1 ()
()
. d  (a − 2) d  a . gcd(a,a − 2) = d
. d 2
a . d =2 d =1 .d =1

a2 + a = a(a +1) ()

.2

: gcd(6k + 5, 7k + 6) k ()
6() 5( )
2( ) 1 ()

: ()

1 = 6× (7k + 6) + (−7) × (6k + 5)

. gcd(6k + 5, 7k + 6) = 1

500 < n < 2000 n ()
: 21
21 ( ) 23 ( ) 72 ( ) 95 ( )

500 :( )

[x ] 500 = 23 21
 21 

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