Determinati numerele intregi x, stiind ca [tex] \frac{11}{2x-1} [/tex] este numar intreg.

Răspuns :

[tex] \frac{11}{2x-1} [/tex] este intreg ⇒ [tex]2x-1|11 [/tex] ⇒ [tex]2x-1 ->D _{11} [/tex] ⇒ [tex]2x-1= {{ -11,-1, 1, 11 } \hbox { /+1}[/tex]

[tex]2x=2,12,-10,0 \hbox { /\div2 }[/tex]

[tex]\boxed {x=1,6,-5,0}[/tex]
2x-1I11
2x-1∈D11
2x-1∈{-11, -1,1,11}
2x-1=-11⇒2x=-11+1⇒x=-10/2⇒x=-5
2x-1=-1⇒2x=1-1⇒x=0
2x-1=1⇒2x=1+1⇒x=2/2⇒x=1
2x-1=11⇒2x=11+1⇒x=12/2⇒x=6
x∈{-5,0,1,6}