Suma = adunare
[tex] \dfrac{1}{2} +\dfrac{5}{6} +(-1) +\left(-\dfrac{2}{3} \right) \\ = \dfrac{1}{2} +\dfrac{5}{6} -1 -\dfrac{2}{3} [/tex]
Numitorul comun e 6, pentru ca 2*3=6
[tex] = \dfrac{3}{6} +\dfrac{5}{6} -\dfrac{6}{6} -\dfrac{4}{6} \\ =\dfrac{3+5-6-4}{6} =\dfrac{-2}{6} =\tt -\dfrac{1}{3} [/tex]
Răspuns: b)
