\[\boxed{\text{373\ (373).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ \sqrt{0,04 \cdot 81 \cdot 25} = 0,2 \cdot 9 \cdot 5 =\]
\[= 9\]
\[\textbf{б)}\ \sqrt{0,09 \cdot 16 \cdot 0,04} =\]
\[= 0,3 \cdot 4 \cdot 0,2 = 0,24\]
\[\textbf{в)}\ \sqrt{1\frac{7}{9} \cdot \frac{4}{25}} = \sqrt{\frac{16}{9} \cdot \frac{4}{25}} = \frac{4}{3} \cdot \frac{2}{5} =\]
\[= \frac{8}{15}\]
\[\textbf{г)}\ \sqrt{\frac{121}{144} \cdot 2\frac{1}{4}} = \sqrt{\frac{121}{144} \cdot \frac{9}{4}} =\]
\[= \frac{11}{12} \cdot \frac{3}{2} = \frac{33}{24} = 1\frac{9}{24} = 1\frac{3}{8}\ \]