( 9/25 - 2,18 ):( 3/4/5 + 0,2) ? 9/25 : 3/4/5 - 2,18:0,2

* Hướng dẫn giải

Lời giải:

Ta có: \[\left( {\frac{9}{{25}} - 2,18} \right):\left( {3\frac{4}{5} + 0,2} \right) = (0,36 - 2,18):(3,8 + 0,2)\]

= (−1,82) : 4 = −0,455 = \(\frac{{ - 91}}{{200}}\);

\[\frac{9}{{25}}:3\frac{4}{5} - 2,18:0,2 = 0,36:3,8 - 2,18:0,2\]

\( = \frac{9}{{95}} - \frac{{109}}{{10}} = \frac{{ - 2053}}{{190}}\).

Ta thấy: \(\frac{{91}}{{200}} < 1\); \(\frac{{2053}}{{190}} > 1\) nên \(\frac{{91}}{{200}} < \frac{{2053}}{{190}}\).

Do đó \(\frac{{ - 91}}{{200}} > \frac{{ - 2053}}{{190}}\).