Điền dấu >, <, = thích hợp vào chỗ chấm.
\[\frac{7}{{12}}\,\, + \,\,2\,\,\,\,\, < \,\,\,\,\,3\,\, - \,\,\frac{1}{3}\] Giải thích: \[\frac{7}{{12}}\,\, + \,\,2 = \frac{7}{{12}}\,\, + \,\,\frac{{24}}{{12}} = \frac{{31}}{{12}}\,\,\] \[3\,\, - \,\,\frac{1}{3} = \frac{9}{3} - \,\,\frac{1}{3} = \frac{8}{3} = \frac{{32}}{{12}}\] Do \[\frac{{31}}{{12}}\,\]< \[\frac{{32}}{{12}}\] nên \[\frac{7}{{12}}\,\, + \,\,2\,\,\,\,\, < \,\,\,\,\,3\,\, - \,\,\frac{1}{3}\]
| \[\frac{4}{9}\,\, \times \,\,\frac{3}{7}\,\,\,\,\, < \,\,\,\,1\] Giải thích: \[\frac{4}{9}\,\, \times \,\,\frac{3}{7}\, = \frac{4}{{21}} < 1\] |
\[\frac{5}{{11}}\,\,:\,\,\frac{3}{{11}}\,\,\,\, < \,\,\,\,2\] Giải thích: \[\frac{5}{{11}}\,\,:\,\,\frac{3}{{11}}\, = \,\frac{5}{{11}} \times \frac{{11}}{3} = \frac{5}{3}\] \(2 = \frac{6}{3}\) Do \[\frac{5}{3}\] < \(\frac{6}{3}\) nên \[\frac{5}{{11}}\,\,:\,\,\frac{3}{{11}}\,\,\,\, < \,\,\,\,2\] | \[5\,\, - \,\,\frac{4}{9}\,\,\,\,\, > \,\,\,\,\frac{5}{3}\,\, + \,\,\frac{5}{9}\] Giải thích: \[5\,\, - \,\,\frac{4}{9} = \frac{{45}}{9} - \,\,\frac{4}{9} = \,\frac{{41}}{9}\] \[\frac{5}{3}\,\, + \,\,\frac{5}{9} = \,\frac{{15}}{9} + \,\,\frac{5}{9} = \frac{{20}}{9}\] Do \[\frac{{41}}{9}\]> \[\frac{{20}}{9}\] nên \[5\,\, - \,\,\frac{4}{9}\,\,\,\,\, > \,\,\,\,\frac{5}{3}\,\, + \,\,\frac{5}{9}\] |