Ответ:

  1. \(\sqrt{\dfrac49\cdot\dfrac{25}{49}}=\sqrt{\dfrac{100}{441}}=\dfrac{10}{21}\).
  2. \(\sqrt{3\dfrac6{25}}=\sqrt{\dfrac{81}{25}}=\dfrac95\).
  3. \(\sqrt{\dfrac{9\cdot0.16}{4}}=\sqrt{0.36}=0.6\).
  4. \(\sqrt{36\cdot144}=\sqrt{5184}=72\).
  5. \(\sqrt{25\cdot32\cdot18}=\sqrt{14400}=120\).
  6. \(\sqrt{1.69\cdot0.01\cdot225}=\sqrt{3.8025}=1.95\).
  7. \(\dfrac{\sqrt5\cdot\sqrt6\cdot\sqrt{30}}{15}=\dfrac{\sqrt{900}}{15}=2\).
  8. \(2\sqrt3\cdot3\sqrt5-4\sqrt{15}=6\sqrt{15}-4\sqrt{15}=2\sqrt{15}\).

Ответ: 1) \(\dfrac{10}{21}\); 2) \(\dfrac95\); 3) 0,6; 4) 72; 5) 120; 6) 1,95; 7) 2; 8) \(2\sqrt{15}\).