5) 11/12 · 21/25 и 2/25 : 2/21

Выполним действия:

\(\frac{11}{12}\cdot\frac{21}{25}=\frac{11\cdot7}{4\cdot25}=\frac{77}{100}\).

\(\frac{2}{25}:\frac{2}{21}=\frac{2}{25}\cdot\frac{21}{2}=\frac{21}{25}=\frac{84}{100}\).

Так как \(\frac{77}{100}<\frac{84}{100}\), то \(\frac{11}{12}\cdot\frac{21}{25}<\frac{2}{25}:\frac{2}{21}\).