Question

Arme e efetue, manualmente: a) 2/3 . 3/5 -1/4= B) 5,2÷(3/7+7)=​

Answer 1

Resposta:

$a) \: \frac{3}{20} = 0.15 \\ \\ b) \: \frac{9.1}{13} = 0.7$

Explicação passo-a-passo:

$a) \: \frac{2}{3} \times \frac{3}{5} - \frac{1}{4 } \\ \frac{6}{15} - \frac{1}{4 } \\ \frac{24 - 15}{60} \\ \frac{9 \div 3}{60 \div 3} \\ \frac{3}{20} = 0.15$

$b) \: 5.2 \div ( \frac{3}{7} + 7) \\ 5.2 \div ( \frac{3}{7} + \frac{7}{1} ) \\ 5.2 \div ( \frac{3 + 49}{7} ) \\ 5.2 \div \frac{52}{7} \\ \frac{5.2}{1} \div \frac{52}{7} \\ \frac{5.2 \times 7}{1 \times 52} \\ \frac{36.4 \div 2}{52 \div 2} \\ \frac{18.2 \div 2}{26 \div 2} \\ \frac{9.1}{1 3} = 0.7$