Ответ:

  1. \(0.8+1.2=2\).
  2. \(0.66+0.04=0.7\).
  3. \(0.666+0.44=1.106\).
  4. \(12.5+23.9=36.4\).
  5. \(14.4-8.9=5.5\).
  6. \(35.4-16.72=18.68\).
  7. \(13.5-8.28=5.22\).
  8. \(38.06-17.4=20.66\).
  9. \(4.5\cdot8.4=37.8\).
  10. \(2.8\cdot5.14=14.392\).
  11. \(3.46\cdot0.14=0.4844\).
  12. \(1.16\cdot0.29=0.3364\).
  13. \(2.4:8=0.3\).
  14. \(0.42:7=0.06\).
  15. \(83.2:6=13.866\ldots\).
  16. \(78.2:34=2.3\).
  17. \(3.2:0.4=8\).
  18. \(0.36:0.9=0.4\).
  19. \(8.4:0.07=120\).
  20. \(28.8:1.8=16\).
  21. \(84:0.35-4.64:5.8-60:48+2.9\cdot0.58=240-0.8-1.25+1.682=239.632\).
  22. \((8.2\cdot0.45+14.71):3.8-49.436=(3.69+14.71):3.8-49.436=18.4:3.8-49.436=4.842105\ldots-49.436=-44.593895\ldots\).

Ответ: 1) 2; 2) 0,7; 3) 1,106; 4) 36,4; 5) 5,5; 6) 18,68; 7) 5,22; 8) 20,66; 9) 37,8; 10) 14,392; 11) 0,4844; 12) 0,3364; 13) 0,3; 14) 0,06; 15) 13,866…; 16) 2,3; 17) 8; 18) 0,4; 19) 120; 20) 16; 21) 239,632; 22) −44,593895….