\(\frac{4}{5}\,\, + \,\,\frac{1}{{10}}\)>\(\frac{1}{2}\)

Giải thích

\(\frac{4}{5}\,\, + \,\,\frac{1}{{10}} = \frac{8}{{10}} + \frac{1}{{10}} = \frac{9}{{10}}\)

\[\frac{1}{2} = \frac{{1 \times 5}}{{2 \times 5}} = \frac{5}{{10}}\]

So sánh: \[\frac{9}{{10}} > \frac{5}{{10}}\]

Vậy: \(\frac{4}{5}\,\, + \,\,\frac{1}{{10}}\)>\(\frac{1}{2}\)

\(\frac{5}{8}\,\, \times \,\,\frac{2}{5}\)<\(\frac{3}{4}\)

Giải thích

\(\frac{5}{8}\,\, \times \,\frac{2}{5} = \frac{{\not 5 \times \not 2}}{{4 \times \not 2 \times \not 5}} = \frac{1}{4}\)

So sánh: \(\frac{1}{4}\,\, < \,\,\frac{3}{4}\)

Vậy: \(\frac{5}{8}\,\, \times \,\frac{2}{5} < \frac{3}{4}\)

\(\frac{1}{2}\,\, - \,\,\frac{1}{4}\) =\(\frac{1}{4}\)

Giải thích

\(\frac{1}{2}\,\, - \,\frac{1}{4} = \frac{2}{4} - \frac{1}{4} = \frac{1}{4}\)

So sánh: \(\frac{1}{4}\,\, = \,\frac{1}{4}\)

Vậy: \(\frac{1}{2} - \frac{1}{4} = \frac{1}{4}\)

\(\frac{3}{4}\,\,:\,\,\frac{6}{9}\,\, - \,\,\frac{1}{2}\) <\(\frac{7}{8}\)

Giải thích

\(\frac{3}{4}\,\,:\frac{6}{9} - \frac{1}{2} = \frac{3}{4} \times \frac{9}{6} - \frac{4}{8} = \frac{{\not 3 \times 9}}{{4 \times \not 3 \times 2}} - \frac{4}{8} = \frac{5}{8}\)

So sánh: \(\frac{5}{8}\,\, < \,\,\frac{7}{8}\)

Vậy: \(\frac{3}{4}:\,\frac{6}{9} - \frac{1}{2} < \frac{7}{8}\)

2/5 của 120 tạ là: A. 40 tạ B. 44 tạ C. 46 tạ D. 48 tạ