Răspuns :
6<=2n+4<40
2n+4>=6 echivalent cu: 2n>=2 echivalent cu n>=1
2n+4<40 echivalent cu 2n<36 echivalent cu n<18
Deci:
A={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17}
2n+4>=6 echivalent cu: 2n>=2 echivalent cu n>=1
2n+4<40 echivalent cu 2n<36 echivalent cu n<18
Deci:
A={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17}