Question

Determinati numerele intregi  x  , stiind ca 11 / 2x-1 (supra) este numar intreg.

Answer 1

11/2x-1 ∈ Z
= 2x-1 I 11
D 11 = {+1,-1,+11,-11}
2x-1 = 1
2x = 2 / :2
x = 1 ∈ Z

2x-1 = -1
2x = -1+1
2x = 0 /:2
x = 0 ∈ Z

2x-1 = 11
2x = 11+1
2x = 12 / :2
x = 6 ∈ Z

2x-1 = -11
2x = -11+1
2x = -10 / :2
x = - 5 ∈ Z
S = {1,0,6,-5}