Question

Tính giá trị của biểu thức:

a) \(\dfrac{4}{7}+\dfrac{9}{14}-\dfrac{5}{7}\)                      b) \(\dfrac{29}{12}-\left(2+\dfrac{1}{4}\right)\)

Answer 1

a) $\frac{4}{7} + \frac{9}{{14}} - \frac{5}{7} = \frac{8}{{14}} + \frac{9}{{14}} - \frac{{10}}{{14}} = \frac{{17}}{{14}} - \frac{{10}}{{14}} = \frac{7}{{14}} = \frac{1}{2}$

b) $\frac{{29}}{{12}} - \left( {2 + \frac{1}{4}} \right) = \frac{{29}}{{12}} - \left( {\frac{8}{4} + \frac{1}{4}} \right) = \frac{{29}}{{12}} - \frac{9}{4} = \frac{{29}}{{12}} - \frac{{27}}{{12}} = \frac{2}{{12}} = \frac{1}{6}$