Tính giá trị biểu thức:a) \(\frac{3}{4}:\frac{{15}}{{24}}\)b) \(\frac{{ - 2}}{3}.\frac{5}{7} + \frac{{ - 2}}{3}.

* Hướng dẫn giải

a) \(\frac{3}{4}:\frac{{15}}{{24}} = \frac{3}{4}.\frac{{24}}{{15}} = \frac{{3.24}}{{4.15}} = \frac{{1.6}}{{1.5}} = \frac{6}{5}\)

b) \(\frac{{ - 2}}{3}.\frac{5}{7} + \frac{{ - 2}}{3}.\frac{2}{7} + \frac{5}{3} = \frac{{ - 2}}{3}.\left( {\frac{5}{7} + \frac{2}{7}} \right) + \frac{5}{3} = \frac{{ - 2}}{3}.\frac{7}{7} + \frac{5}{3} = \frac{{ - 2}}{3} + \frac{5}{3} = \frac{3}{3} = 3\)