Question

1) Efetue:
$\frac{2}{3} + \frac{1}{2}$
$\frac{2}{5} - \frac{1}{4}$
$\frac{3}{4} + \frac{1}{3} - \frac{3}{2}$
$\frac{3}{5} + \frac{5}{4} - \frac{4}{3}$
$( \frac{5}{6} - \frac{3}{8} ) \times \frac{2}{7}$

Answer 1

$\frac{2}{3}+\frac{1}{2}=\frac{4+3}{6}=\frac{7}{6}\\ \\ \frac{2}{5}-\frac{1}{4}=\frac{8-5}{20}=\frac{3}{20}\\ \\ \frac{3}{4}+\frac{1}{3}-\frac{3}{2}=\frac{9+4-18}{12}=-\frac{5}{12}\\ \\ \frac{3}{5}+\frac{5}{4}-\frac{4}{3}=\frac{36+75-40}{60}=\frac{71}{60}\\ \\ \left(\frac{5}{6}-\frac{3}{8}\right)\times\frac{2}{7}=\frac{20-9}{24} \times\frac{2}{7}=\frac{11}{24} \times\frac{2}{7}=\frac{11}{84}$