Ответ:

  1. \(\sqrt{360}\cdot\sqrt{2.5}=\sqrt{900}=30\).
  2. \(\sqrt{90\cdot4.9}=\sqrt{441}=21\).
  3. \(\sqrt{72\cdot32}=\sqrt{2304}=48\).
  4. \(\sqrt{3.6\cdot12.1}=\sqrt{43.56}=6.6\).
  5. \(\sqrt{13}\cdot\sqrt{52}=\sqrt{676}=26\).
  6. \(\sqrt{63}\cdot\sqrt7=\sqrt{441}=21\).
  7. \(\sqrt{\frac23}\cdot\sqrt{\frac38}=\sqrt{\frac14}=\frac12\).
  8. \(\sqrt{1.2}\cdot\sqrt{3\frac13}=\sqrt{1.2\cdot\frac{10}{3}}=\sqrt4=2\).
  9. \(\sqrt{20}\cdot\sqrt{45}=\sqrt{900}=30\).

Ответ: 1) 30; 2) 21; 3) 48; 4) 6,6; 5) 26; 6) 21; 7) 0,5; 8) 2; 9) 30.