Ответ:

Используем свойство: \(\sqrt{ab}=\sqrt a\cdot\sqrt b\).

  1. а) \(\sqrt{9\cdot36}=3\cdot6=18\); б) \(\sqrt{25\cdot81}=5\cdot9=45\); в) \(\sqrt{16\cdot900}=4\cdot30=120\); г) \(\sqrt{2500\cdot49}=50\cdot7=350\).
  2. а) \(\sqrt{0.64\cdot0.25}=0.8\cdot0.5=0.4\); б) \(\sqrt{0.49\cdot16}=0.7\cdot4=2.8\); в) \(\sqrt{9\cdot1.21}=3\cdot1.1=3.3\); г) \(\sqrt{400\cdot0.36}=20\cdot0.6=12\).
  3. а) \(\sqrt{0.09\cdot0.25}=0.3\cdot0.5=0.15\); б) \(\sqrt{0.81\cdot0.04}=0.9\cdot0.2=0.18\); в) \(\sqrt{6.25\cdot0.16}=2.5\cdot0.4=1\); г) \(\sqrt{0.36\cdot1.44}=0.6\cdot1.2=0.72\).
  4. а) \(\sqrt{25\cdot16\cdot0.36}=5\cdot4\cdot0.6=12\); б) \(\sqrt{196\cdot2.25\cdot0.09}=14\cdot1.5\cdot0.3=6.3\); в) \(\sqrt{1.69\cdot0.04\cdot0.0001}=1.3\cdot0.2\cdot0.01=0.0026\).

Ответ: 1) 18; 45; 120; 350. 2) 0,4; 2,8; 3,3; 12. 3) 0,15; 0,18; 1; 0,72. 4) 12; 6,3; 0,0026.