Ex5 dau coroana va roggg e urgentt

[tex]\it b)\ \ \dfrac{1}{7}+\dfrac{2}{7}+\dfrac{3}{7}=\dfrac{6}{7}\\ \\ \\ d)\ \ \dfrac{1}{6} +\dfrac{2}{6}+\dfrac{3}{6}=\dfrac{6}{6}=1[/tex]