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# Dodawanie i odejmowanie ułamków zwykłych – Zadanie 3 obliczenia

Wykonaj odejmowanie podanych wyrażeń:

a) $$4\dfrac{1}{2}-1\dfrac{2}{5}$$

b) $$7\dfrac{5}{6}-4\dfrac{3}{4}$$

c) $$4\dfrac{2}{3}-4\dfrac{2}{7}$$

d) $$11\dfrac{9}{13}-5\dfrac{1}{2}$$

e) $$20\dfrac{5}{14}-13\dfrac{1}{6}$$

Rozwiązanie
a)
$$4\dfrac{1}{2}-1\dfrac{2}{5}= 4\dfrac{1}{2}_{\: / \: \cdot 5}-1\dfrac{2}{5}_{\: / \: \cdot 2}= 4\dfrac{5}{10}-1\dfrac{4}{10}=3\dfrac{1}{10}$$

b)
$$7\dfrac{5}{6}-4\dfrac{3}{4}= 7\dfrac{5}{6}_{\: / \: \cdot 2}-4\dfrac{3}{4}_{\: / \: \cdot 3}= 7\dfrac{10}{12}-4\dfrac{9}{12}=3\dfrac{1}{12}$$

c)
$$4\dfrac{2}{3}-4\dfrac{2}{7}= 4\dfrac{2}{3}_{\: / \: \cdot 7}-4\dfrac{2}{7}_{\: / \: \cdot 3}= 4\dfrac{14}{21}-4\dfrac{6}{21}=\dfrac{8}{21}$$

d)
$$11\dfrac{9}{13}-5\dfrac{1}{2}= 11\dfrac{9}{13}_{\: / \: \cdot 2}-5\dfrac{1}{2}_{\: / \: \cdot 13}= 11\dfrac{18}{26}-5\dfrac{13}{26}=6\dfrac{5}{26}$$

e)
$$20\dfrac{5}{14}-13\dfrac{1}{6}= 20\dfrac{5}{14}_{\: / \: \cdot 3}-13\dfrac{1}{6}_{\: / \: \cdot 7}= 20\dfrac{15}{42}-13\dfrac{7}{42}=7\dfrac{8}{42}$$

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