C=xIx∈N si 125 divizibil cu (2*x+1)
divizorii lui 125 sunt: 1,5,25,125.
2*x+1=1 => 2x+1=1 => 2x=1-1 => 2x=0 => x=0:2 => x=0
2*x+1=5 => 2x+1=5 => 2x=5-1 => 2x=4 => x=4:2 => x=2
2*x+1=25 => 2x+1=25 => 2x=25-1 => 2x=24 => x=24:2 => x=12
2*x+1=125 => 2x+1=125 => 2x=125-1 => 2x=124 => x=124:2 => x=62
C={0,2,12,62}