Đề bài

Tính: a) \(11\frac{2}{3} + \frac{{ - 5}}{6}\) b) \(\frac{5}{8} - 2\frac{3}{4}\) c) \(7\frac{1}{5}.4\frac{5}{9}\) d) \(3\frac{4}{7}:\frac{{20}}{{ - 9}}\)

Lời giải chi tiết

a) \(11\frac{2}{3} + \frac{{ - 5}}{6} = \frac{{35}}{3} + \frac{{ - 5}}{6} = \frac{{70}}{6} + \frac{{ - 5}}{6} = \frac{{65}}{6}\)b) \(\frac{5}{8} - 2\frac{3}{4} = \frac{5}{8} - \frac{{11}}{4} = \frac{5}{8} - \frac{{22}}{8} = \frac{{ - 17}}{8}\)c) \(7\frac{1}{5}.4\frac{5}{9} = \frac{{36}}{5}.\frac{{41}}{9} = \frac{{36.41}}{{5.9}} = \frac{{164}}{5}\)d) \(3\frac{4}{7}:\frac{{20}}{{ - 9}} = \frac{{25}}{7}:\frac{{20}}{{ - 9}} = \frac{{25}}{7}.\frac{{ - 9}}{{20}} = \frac{{ - 45}}{{28}}\)