Question

Determinati valorile lui x ∈ N pentru care $\frac{6}{2x-1}$ ∈ N .

Answer 1

6/(2x-1) € N=> (2x-1) l 6=> (2x-1)€ D6(D indice 6)
D6={1;2;3;6}
1.2x-1=1
2x=2 l :2
x=1 ; A
2.2x-1=2
2x=3
x=3/2 ; F 3/2 nu apartine N
3.2x-1=3
2x=4 l:2
x=2 ; A
4. 2x-1=6
2x=7
x=7/2; F 7/2 nu apartine N=> x€{1;2}