Question

Calcular e apresentar o resultado sob a forma de fracção irredutível : a) 5/3×7/4×1/2÷3

b)(1/2)2 + 1/2÷3/7 -1

Answer 1

a) $\frac{\frac{5}{3} . \frac{7}{4} . \frac{1}{2}}{3} = {\frac{5}{3} . \frac{7}{4} . \frac{1}{2} . \frac{1}{3} = \frac{35}{72}$

b) $\frac {2.\frac{1}{2} + \frac{1}{2}}{\frac {3}{7}} - 1 = \frac{\frac{3}{2} }{\frac{3}{7} } -1 = \frac{3}{2} .\frac{7}{3} - 1 = \frac{7}{2} - 1 =  \frac{7}{2} - \frac{2}{2} = \frac{5}{2}$ ou 2,5

Answer 2

$\dfrac{5}{3} * \dfrac{7}{4} * \dfrac{1}{2} \div 3 \\ \\ \\ \dfrac{5 * 7 * 1}{3 * 4 * 2} \div 3 \\ \\ \\ \dfrac{35}{24} \div 3$

3 esta dividindo inverte em forma de fração e passa multiplicando:

$\dfrac{35}{24} * \dfrac{1}{3} \\ \\ \\ => \dfrac{35}{72}$

====

$\dfrac{1}{2} * 2 + \dfrac{1}{2} \div \dfrac{3}{7} - 1 \\ \\ \\ \dfrac{2}{2} + \dfrac{1}{2} * \dfrac{7}{3} - 1 \\ \\ \\ \not 1 + \dfrac{7}{6} -\not 1 \\ \\ \\ => \dfrac{7}{6}$