Explicație pas cu pas:
(4n+23)/(2n+1)€Z <=>2n+1|4n+23
2n+1|4n+23
2n+1|2n+1=>2n+1|4n+2
Le scadem:
2n+1|4n+23-4n-2=>2n+1|21 =>2n+1€D21 in Z =>
2n+1€{-21,-7,-3,-1,1,7,21} =>
2n€{-22,-8,-4,-2,0,6,20} =>
n€{-11,-4,-2,-1,0,3,10}
(5n+8)/(2n-1)€Z<=>2n-1|5n+8
2n-1|5n+8=>2n-1|10n+16
2n-1|2n-1=>2n-1|10n-5
Le scadem:
2n-1|10n+16-10n+5 => 2n-1|21 =>2n-1€D21 in Z =>
2n-1€{-21,-7,-3,-1,1,3,7,21} =>
2n€{-20,-6,-2,0,2,4,8,22} =>
n€{-10,-3,-1,0,1,2,4,11}
