Đáp án:
$a)\dfrac{{ - 23}}{{114}} < \dfrac{{ - 18}}{{91}};b)\dfrac{{ - 22}}{{35}} < \dfrac{{ - 103}}{{177}}$
Giải thích các bước giải:
Ta có:
$\begin{array}{l}
a)\dfrac{{ - 18}}{{91}} = \dfrac{{ - 18.114}}{{91.114}} = \dfrac{{ - 2052}}{{10374}};\dfrac{{ - 23}}{{114}} = \dfrac{{ - 23.91}}{{114.91}} = \dfrac{{ - 2093}}{{10374}}\\
- 2093 < - 2052 \Rightarrow \dfrac{{ - 2093}}{{10374}} < \dfrac{{ - 2052}}{{10374}}\\
\Rightarrow \dfrac{{ - 23}}{{114}} < \dfrac{{ - 18}}{{91}}\\
b)\dfrac{{ - 22}}{{35}} = \dfrac{{ - 22.177}}{{35.177}} = \dfrac{{ - 3894}}{{6195}};\dfrac{{ - 103}}{{177}} = \dfrac{{ - 103.35}}{{177.35}} = \dfrac{{ - 3605}}{{6195}}\\
- 3894 < - 3605 \Rightarrow \dfrac{{ - 3894}}{{6195}} < \dfrac{{ - 3605}}{{6195}}\\
\Rightarrow \dfrac{{ - 22}}{{35}} < \dfrac{{ - 103}}{{177}}
\end{array}$
