Ответ:

  1. \(\sqrt{16\cdot0.25\cdot121}=\sqrt{4\cdot121}=\sqrt{484}=22\).

  2. \(\sqrt{1.96\cdot0.01\cdot400}=\sqrt{7.84}=2.8\).

  3. \(\sqrt{1.96\cdot\frac{9}{49}\cdot1.44}=\sqrt{\left(1.4\cdot\frac{3}{7}\cdot1.2\right)^2}=1.4\cdot\frac{3}{7}\cdot1.2=0.72\).

  4. \(\sqrt{2.25\cdot\frac{196}{81}\cdot\frac{9}{25}}=\sqrt{\left(1.5\cdot\frac{14}{9}\cdot\frac{3}{5}\right)^2}=1.4\).

Ответ: 1) 22; 2) 2,8; 3) 0,72; 4) 1,4.