Ответ:

  1. \(\frac16+\frac13=\frac16+\frac26=\frac12\).
  2. \(2-\frac56=1\frac66-\frac56=1\frac16\).
  3. \(5\frac13+6\frac56=\frac{32}{6}+\frac{41}{6}=\frac{73}{6}=12\frac16\).
  4. \(2\frac1{15}-\frac8{45}=\frac{93}{45}-\frac8{45}=\frac{85}{45}=\frac{17}{9}=1\frac89\).
  5. \(\frac97\times\frac23=\frac{18}{21}=\frac67\). Correction: \(\frac{18}{21}=\frac67\).
  6. \(7\frac12\times1\frac1{25}=\frac{15}{2}\times\frac{26}{25}=\frac{39}{5}=7\frac45\).
  7. \(\frac7{16}:\frac{21}{32}=\frac7{16}\times\frac{32}{21}=\frac23\).
  8. \(3\frac12:2=\frac72\times\frac12=\frac74=1\frac34\).

Ответ: 1) \(\frac12\); 2) \(1\frac16\); 3) \(12\frac16\); 4) \(1\frac89\); 5) \(\frac67\); 6) \(7\frac45\); 7) \(\frac23\); 8) \(1\frac34\).