Question

Aflati nr. care apartin multimi Z daca 6 ( supra ) 2n-1 

Answer 1

2n-1∈D6
D6={1,2,3,6}
pt.2n-1=1⇒2n=1+1⇒n=2/2⇒n=1∈Z
pt.2n-1=2⇒2n=2+1⇒n=3/2∉Z
2n-1=3⇒2n=3+1⇒n=2∈Z
2n-1=6⇒2n=6+1⇒=7/2∉Z
Z={1,2}