1.[tex] \frac{1}{2}+ \frac{3}{4}- \frac{1}{5}= \frac{10}{20} + \frac{15}{20}- \frac{4}{20} = \frac{21}{20} [/tex] Observatie: Am amplificat fractiile si am adus ca numitor comun 20.
2.Acum, avem [tex]1- \frac{1}{3}+ \frac{1}{2}- \frac{1}{5}+ \frac{1}{4}= \frac{60}{60}- \frac{20}{60}+ \frac{30}{60}- \frac{12}{60} + \frac{15}{60}= \frac{73}{60} [/tex]
