- \(\sqrt{36\cdot81}=\sqrt{36}\cdot\sqrt{81}=6\cdot9=54\).
- \(\sqrt{900\cdot49}=30\cdot7=210\).
- \(\sqrt{16\cdot0.25}=4\cdot0.5=2\).
- \(\sqrt{9\cdot1.69}=3\cdot1.3=3.9\).
- \(\sqrt{0.36\cdot1.21}=0.6\cdot1.1=0.66\).
- \(\sqrt{5^2\cdot3^6}=5\cdot3^3=5\cdot27=135\).
- \(\sqrt{4^4\cdot3^2}=4^2\cdot3=16\cdot3=48\).
- \(\sqrt{2^6\cdot5^2}=2^3\cdot5=8\cdot5=40\).
- \(\sqrt{2.25\cdot0.04\cdot1600}=1.5\cdot0.2\cdot40=12\).
- \(13\frac49=\frac{121}{9}\), поэтому \(\sqrt{13\frac49}=\sqrt{\frac{121}{9}}=\frac{11}{3}=3\frac23\).
- \(1\frac79=\frac{16}{9}\), поэтому \(\sqrt{1\frac79\cdot\frac4{25}}=\sqrt{\frac{16}{9}\cdot\frac4{25}}=\sqrt{\frac{64}{225}}=\frac8{15}\).
- \(\sqrt{\frac1{16}\cdot\frac9{25}}=\sqrt{\frac9{400}}=\frac3{20}\).
Ответ: 1) 54; 2) 210; 3) 2; 4) 3,9; 5) 0,66; 6) 135; 7) 48; 8) 40; 9) 12; 10) \(3\frac23\); 11) \(\frac8{15}\); 12) \(\frac3{20}\).