4.5. Вычислите, выбрав удобный порядок вычислений: A) 12-14-18 Б)-13+14-15 B)-16-17+20 Г) -20-10+40 Д)-15-16+35 E)-15-16-35 E)-23-21+14 Ж)-10-19+13 3)-18-10+14+15 И) -13+16-15-8 Й) -20+67-57-18 K)-14-10+12-11 Л)-20-19-13 M)-25-35-45 H)-13-45-67-9 O)-4-9-19-12 П)-1.12-1,14+2,01 P)-1,3+3,7-8.9 C) -1,4-3,22+8,07 T) 9,01-4.5-12.3 1 3--4 2 3 4 1 -2- 8 1 3 Φ) -5-6--6 X)-10-5/+10/- Ч)-3.8-9.23-10,1 93 2 5 12 7 II)-171-1970-11 ID-20-111-3 18 3 2 I)-2,3-4,6-8 b)-23,3-45,09-1,01-2,5 1 1 3)-7-13+3+23 4 bl)-3+5-3+ 7 7 b)-5-6-7- 11 - 11 10 21 32 + 11 22 33 10)-4-4.2+5-9.1+10)

Решим предложенные примеры:

1. A) $$12-14-18 = 12 - (14 + 18) = 12 - 32 = -20$$
2. Б) $$-13+14-15 = 1 - 15 = -14$$
3. B) $$-16-17+20 = -33 + 20 = -13$$
4. Г) $$-20-10+40 = -30 + 40 = 10$$
5. Д) $$-15-16+35 = -31 + 35 = 4$$
6. E) $$-15-16-35 = -31 - 35 = -66$$
7. Ё) $$-23-21+14 = -44 + 14 = -30$$
8. Ж) $$-10-19+13 = -29 + 13 = -16$$
9. З) $$-18-10+14+15 = -28 + 29 = 1$$
10. И) $$-13+16-15-8 = 3 - 23 = -20$$
11. Й) $$-20+67-57-18 = 47 - 75 = -28$$
12. К) $$-14-10+12-11 = -24 + 1 = -23$$
13. Л) $$-20-19-13 = -39 - 13 = -52$$
14. M) $$-25-35-45 = -60 - 45 = -105$$
15. H) $$-13-45-67-9 = -58 - 76 = -134$$
16. O) $$-4-9-19-12 = -13 - 31 = -44$$
17. П) $$-1.12-1,14+2,01 = -2,26 + 2,01 = -0,25$$
18. P) $$-1,3+3,7-8.9 = 2,4 - 8,9 = -6,5$$
19. C) $$-1,4-3,22+8,07 = -4,62 + 8,07 = 3,45$$
20. T) $$9,01-4.5-12.3 = 4,51 - 12,3 = -7,79$$
21. У) $$3\frac{1}{2}-4\frac{3}{4}-2\frac{1}{8} = \frac{7}{2}-\frac{19}{4}-\frac{17}{8} = \frac{7 \cdot 4}{2 \cdot 4}-\frac{19 \cdot 2}{4 \cdot 2}-\frac{17}{8} = \frac{28}{8}-\frac{38}{8}-\frac{17}{8} = \frac{28-38-17}{8} = \frac{-27}{8} = -3\frac{3}{8}$$
22. Ф) $$-5\frac{1}{3}+6\frac{4}{9}-6\frac{1}{2} = -\frac{16}{3} + \frac{58}{9} - \frac{13}{2} = -\frac{16 \cdot 6}{3 \cdot 6} + \frac{58 \cdot 2}{9 \cdot 2} - \frac{13 \cdot 9}{2 \cdot 9} = -\frac{96}{18} + \frac{116}{18} - \frac{117}{18} = \frac{-96+116-117}{18} = \frac{-97}{18} = -5\frac{7}{18}$$
23. Ч) $$-3.8-9.23-10,1 = -13,03 - 10,1 = -23,13$$
24. Ш) $$-17\frac{5}{12}-19\frac{7}{18}+11 = -\frac{209}{12} - \frac{349}{18} + 11 = -\frac{209 \cdot 3}{12 \cdot 3} - \frac{349 \cdot 2}{18 \cdot 2} + \frac{11 \cdot 36}{1 \cdot 36} = -\frac{627}{36} - \frac{698}{36} + \frac{396}{36} = \frac{-627-698+396}{36} = \frac{-929}{36} = -25\frac{29}{36}$$
25. Щ) $$-20\frac{1}{3}-11\frac{1}{2} = -\frac{61}{3} - \frac{23}{2} = -\frac{61 \cdot 2}{3 \cdot 2} - \frac{23 \cdot 3}{2 \cdot 3} = -\frac{122}{6} - \frac{69}{6} = \frac{-122-69}{6} = \frac{-191}{6} = -31\frac{5}{6}$$
26. Ы) $$-23,3-45,09-1,01-2,5 = -68,39 - 3,51 = -71,9$$
27. Б) $$-3\frac{5}{7}+5\frac{2}{4}-3\frac{5}{11} = -\frac{26}{7} + \frac{22}{4} - \frac{38}{11} = -\frac{26 \cdot 44}{7 \cdot 44} + \frac{22 \cdot 77}{4 \cdot 77} - \frac{38 \cdot 28}{11 \cdot 28} = -\frac{1144}{308} + \frac{1694}{308} - \frac{1064}{308} = \frac{-1144+1694-1064}{308} = \frac{-514}{308} = -1\frac{206}{308} = -1\frac{103}{154}$$
28. Я) $$-5\frac{3}{11}+6\frac{4}{11}-7\frac{5}{11}-8\frac{6}{11} = -\frac{58}{11} + \frac{70}{11} - \frac{82}{11} - \frac{94}{11} = \frac{-58+70-82-94}{11} = \frac{-164}{11} = -14\frac{10}{11}$$
29. Э) $$-7\frac{1}{2}+3+2\frac{1}{3}+2\frac{4}{5} = -\frac{15}{2} + 3 + \frac{7}{3} + \frac{14}{5} = -\frac{15 \cdot 15}{2 \cdot 15} + \frac{3 \cdot 30}{1 \cdot 30} + \frac{7 \cdot 10}{3 \cdot 10} + \frac{14 \cdot 6}{5 \cdot 6} = -\frac{225}{30} + \frac{90}{30} + \frac{70}{30} + \frac{84}{30} = \frac{-225+90+70+84}{30} = \frac{19}{30}$$
30. Ю) $$-4\frac{2}{3}+5\frac{2}{7}+4 = -\frac{14}{3} + \frac{37}{7} + 4 = -\frac{14 \cdot 7}{3 \cdot 7} + \frac{37 \cdot 3}{7 \cdot 3} + \frac{4 \cdot 21}{1 \cdot 21} = -\frac{98}{21} + \frac{111}{21} + \frac{84}{21} = \frac{-98+111+84}{21} = \frac{97}{21} = 4\frac{13}{21}$$

Ответ: вычисления выполнены.