a) Rút gọn phân số:     \(\frac{{( - 4).25}}{{15.

* Hướng dẫn giải

a) \(\frac{{( - 4).25}}{{15.24}}\)

\(\begin{array}{l}
 = \frac{{( - 4).5.5}}{{3.5.4.6}}\\
 = \frac{{( - 1).5}}{{3.6}} = \frac{{ - 5}}{{18}}
\end{array}\)

b) \(\frac{{ - 2}}{3} = \frac{{ - 2.4}}{{3.4}} = \frac{{ - 8}}{{12}}\);  \(\frac{{ - 3}}{4} = \frac{{ - 3.3}}{{4.3}} = \frac{{ - 9}}{{12}}\)

Ta có: \(-8 > -9\) nên \(\frac{{ - 8}}{{12}} < \frac{{ - 9}}{{12}}\)

Vậy \(\frac{{ - 2}}{3} > \frac{{ - 3}}{4}\)