Răspuns:
a.
numitorul comun este 12
[tex]( \frac{1}{2} + \frac{3}{4} + \frac{5}{6} ) + ( \frac{1}{2} + \frac{1}{4} + \frac{1}{6}) = \frac{25}{12} + \frac{11}{12} = \frac{25 + 11}{12} = \frac{36}{12} = 3[/tex]
b. cmmnc este 90
[tex]( \frac{3}{2} + \frac{7}{5} + \frac{5}{9} ) + ( \frac{3}{2} + \frac{8}{5} + \frac{22}{9} ) = \frac{135 + 126 + 50}{90} + \frac{135 + 144 + 220}{90} = \frac{311}{90} + \frac{499}{90} = \frac{311 + 499}{90} = \frac{810}{90} = 9[/tex]
