Tính bằng cách thuận tiện.
Giải thích
a) \[\frac{3}{5}\,\, + \,\,\frac{{14}}{7}\,\, + \,\,\frac{4}{{10}}\] = \[(\frac{3}{5}\,\, + \,\,\frac{4}{{10}})\,\, + \,\,\frac{{14}}{7}\] = 1 + 2 = 3 | b) \[\frac{1}{7}\,\, + \,\,\frac{2}{7}\,\, + \,\,\frac{3}{7}\,\, + \,\,\frac{4}{7}\,\, + \,\,\frac{5}{7}\,\, + \,\,\frac{6}{7}\] = \[(\frac{1}{7}\,\, + \,\,\frac{6}{7})\,\, + \,\,(\frac{2}{7}\,\, + \,\,\frac{5}{7})\,\, + \,\,(\frac{3}{7}\,\, + \,\,\frac{4}{7})\] = 1 + 1 + 1 = 3 |