Đáp án:
\(\begin{array}{l}
Bai\,\,1:\,\,\\
- \frac{1}{2} < 0 < \frac{{ - 5}}{{ - 10}} < 0,25\\
Bai\,\,2:\,\,\,\,1
\end{array}\)
Giải thích các bước giải:
\[\begin{array}{l}
Bai\,\,1:\,\,\\
- \frac{1}{2} < 0\\
\frac{{ - 1}}{{ - 5}} = 0,2 < 0,25\\
\Rightarrow - \frac{1}{2} < 0 < \frac{{ - 5}}{{ - 10}} < 0,25\\
Bai\,\,2:\,\,\\
- \left( {\frac{2}{5} - \frac{3}{4}} \right) + \left( {\frac{5}{4} - \frac{3}{5}} \right)\\
= - \frac{2}{5} + \frac{3}{4} + \frac{5}{4} - \frac{3}{5}\\
= \frac{{ - 2 - 3}}{5} + \frac{{3 + 5}}{4}\\
= \frac{{ - 5}}{5} + \frac{8}{4}\\
= - 1 + 2 = 1
\end{array}\]
