Question

4n+7/2n-1 apartine de Z raspuns imediat va rog

Answer 1

Explicație pas cu pas:

4n+7/2n-1€Z <=>2n-1|4n+7 dar 2n-1|2n-1

deci avem:

2n-1|4n+7

2n-1|2n-1 /×2 => 2n-1|4n-2

Le scadem si avem :

2n-1|4n+7-4n+2 => 2n-1|9 =>2n-1€D9 in Z => 2n-1€{-9,-3,-1,1,3,9} =>

2n€{-8,-2,0,2,4,10} => n€{-4,-1,0,1,2,5}