Question

Resolva as expressões abaixo:

a)-2/3+(-1/7)÷(3/4)
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2+3/2

b)1/2+(3/5)×(2/9)-2/5
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3+1/2

Answer 1

a)

$- \frac{ \frac{2}{3} + ( - \frac{1}{7}) \div ( \frac{3}{4} ) }{2 + \frac{3}{2} } = \\ \\ -\frac{ - \frac{2}{3} - \frac{1}{7} \times \frac{4}{3} }{ \frac{7}{2} } = \\ \\ \frac{ - \frac{2}{3} - \frac{4}{21} }{ \frac{7}{2} } = \\ \\ \frac{ - \frac{6}{7} }{ \frac{7}{2} } = \\ \\ - \frac{12}{49}$
b)

$\frac{ \frac{1}{2} + ( \frac{3}{5} ) \times ( \frac{2}{9} - \frac{2}{5} }{3 + \frac{1}{2} } = \\ \\ \frac{ \frac{1}{2} + \frac{1}{5} \times \frac{2}{3} - \frac{2}{5} }{ \frac{5}{2} } = \\ \\ \frac{ \frac{1}{2} + \frac{2}{15} - \frac{2}{5} }{ \frac{5}{2} } = \\ \\ \frac{ \frac{7}{30} }{ \frac{5}{2} } = \\ \\ \frac{7}{75}$