Respostas

2014-07-08T02:04:51-03:00
E aí mano,

transforme as frações mistas em fração imprópria, em seguida tire o MMC se necessário:


2 \dfrac{1}{2}- \dfrac{3}{5}~~\to~~\dfrac{2*2+1}{2}- \dfrac{3}{5}~~\to~~ \dfrac{4+1}{2}- \dfrac{3}{5}~~\to~~ \dfrac{5}{2}- \dfrac{3}{5}\\\\
MMC(2,5)=10:\\\\
 \dfrac{5*5-2*3}{10}~~\to~~ \dfrac{25-6}{10}~~\to~~ \dfrac{19}{10}

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2 \dfrac{3}{5}- \dfrac{3}{10}~~\to~~ \dfrac{2*5+3}{5}- \dfrac{3}{10}~~\to~~ \dfrac{15+3}{5}- \dfrac{3}{10}~~\to~~ \dfrac{18}{5}- \dfrac{3}{10}\\\\
MMC(5,10)=10\\\\
 \dfrac{2*18-1*3}{10}~~\to~~ \dfrac{36-3}{10}~~\to~~ \dfrac{33}{10}

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8+ \dfrac{1}{3}- \dfrac{3}{4}~~\to~~ \dfrac{8*3+1}{3}- \dfrac{3}{4}~~\to~~ \dfrac{24+1}{3}- \dfrac{3}{4}~~\to~~ \dfrac{25}{3}- \dfrac{3}{4}\\\\
MMC(3,4)=12\\\\
 \dfrac{4*25-3*3}{12}~~\to~~ \dfrac{100-9}{12}~~\to~~ \dfrac{81}{12}= \dfrac{81:3}{12:3}= \dfrac{27}{4}

Espero ter ajudado e tenha ótimos estudos =))
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