Ответ:

  1. \(0.79+3.018=3.808\).
  2. \(4.1-2.8=1.3\).
  3. \(1.8\cdot0.3=0.54\).
  4. \(5.4:6=0.9\).
  5. \(72:0.9=80\).
  6. \(9:4=2.25=2\frac{1}{4}\).
  7. \(10:\frac{5}{11}=10\cdot\frac{11}{5}=22\).
  8. \(2\frac{3}{8}+4\frac{1}{6}=6+\frac{9}{24}+\frac{4}{24}=6\frac{13}{24}\).
  9. \(6-1\frac{3}{5}=5-\frac{3}{5}=4\frac{2}{5}\).

Ответ: 1) 3,808; 2) 1,3; 3) 0,54; 4) 0,9; 5) 80; 6) 2\(\frac{1}{4}\); 7) 22; 8) 6\(\frac{13}{24}\); 9) 4\(\frac{2}{5}\).