Răspuns :
[tex] \frac{1}{2} + \frac{1}{3} + \frac{1}{6} = \frac{3}{6} + \frac{2}{6} + \frac{1}{6} = \frac{6}{6} =1[/tex]
[tex] \frac{1}{2}+ \frac{1}{3}+ \frac{1}{6}= \frac{3}{6}+ \frac{2}{6}+ \frac{1}{6}= \frac{3+2+1}{6}= \frac{6}{6}=1. [/tex]