Question

2×n+1 divide pe 18sa se gaseasca n

Answer 1

Deci 2xn+1€D18={1,2,3,6,9,18}
-1
2xn€{0,1,2,5,8,17}
:2
n€{0,1/2,1,5/2,4,17/2}
Dar dacă n este natural
Atunci
n€{0,1,4}

Answer 2

2n+1=3 n=1 2n+1=9 n=4 R=n=1;4