Задание 1. Найдите значение выражения Задание 2. Найдите значение выражения

Определим предмет: математика.

Задание 1. Найдите значение выражения

1. $$rac{3}{4} cdot rac{6}{5} = rac{3 cdot 6}{4 cdot 5} = rac{18}{20} = rac{9}{10} = 0,9$$
2. $$rac{21}{5} : rac{3}{7} = rac{21}{5} cdot rac{7}{3} = rac{21 cdot 7}{5 cdot 3} = rac{7 cdot 7}{5 cdot 1} = rac{49}{5} = 9,8$$
3. $$3,25 cdot rac{4}{5} = rac{325}{100} cdot rac{4}{5} = rac{13 cdot 4}{4 cdot 5} = rac{13}{5} = 2,6$$
4. $$9 rac{2}{5} cdot 3 = rac{47}{5} cdot 3 = rac{47 cdot 3}{5} = rac{141}{5} = 28,2$$
5. $$5 rac{9}{32} = 5,28125$$
6. $$7 rac{12}{5} cdot 35 = rac{47}{5} cdot 35 = 47 cdot 7 = 329$$
7. $$12, rac{15}{5} : 2 = rac{75}{5} : 2 = 15 : 2 = 7,5$$
8. $$6, rac{4}{5} : 11 = rac{34}{5} : 11 = rac{34}{5} cdot rac{1}{11} = rac{34}{55} approx 0,62$$
9. $$3, rac{4}{5} : 35 = rac{19}{5} : 35 = rac{19}{5} cdot rac{1}{35} = rac{19}{175} approx 0,11$$
10. $$15, rac{3}{4} cdot 7 = rac{63}{4} cdot 7 = rac{63 cdot 7}{4} = rac{441}{4} = 110,25$$
11. $$21, rac{3}{2} : 5 = rac{45}{2} : 5 = rac{45}{2} cdot rac{1}{5} = rac{9}{2} = 4,5$$
12. $$14, rac{7}{5} : 2 = rac{77}{5} : 2 = rac{77}{5} cdot rac{1}{2} = rac{77}{10} = 7,7$$
13. $$1, rac{3}{4} cdot 25 = rac{7}{4} cdot 25 = rac{7 cdot 25}{4} = rac{175}{4} = 43,75$$
14. $$1, rac{27}{5} cdot 50 = rac{32}{5} cdot 50 = 32 cdot 10 = 320$$
15. $$1, rac{9}{2} cdot 25 = rac{11}{2} cdot 25 = rac{11 cdot 25}{2} = rac{275}{2} = 137,5$$
16. $$1, rac{1}{5} cdot 4 = rac{6}{5} cdot 4 = rac{6 cdot 4}{5} = rac{24}{5} = 4,8$$
17. $$1, rac{13}{2} cdot 50 = rac{15}{2} cdot 50 = 15 cdot 25 = 375$$
18. $$1, rac{23}{10} cdot 20 = rac{33}{10} cdot 20 = 33 cdot 2 = 66$$
19. $$rac{14}{25} cdot rac{8}{25} = rac{112}{625} = 0,1792$$
20. $$rac{9}{4} cdot rac{8}{25} = rac{9 cdot 2}{25} = rac{18}{25} = 0,72$$
21. $$rac{4}{5} cdot rac{11}{12} = rac{1 cdot 11}{5 cdot 3} = rac{11}{15} approx 0,73$$
22. $$rac{1}{10} cdot rac{20}{50} = rac{20}{500} = rac{2}{50} = rac{1}{25} = 0,04$$
23. $$3, rac{7}{4} cdot rac{4}{25} = rac{19}{4} cdot rac{4}{25} = rac{19}{25} = 0,76$$
24. $$4, rac{115}{25} cdot rac{4}{25} = rac{215}{25} cdot rac{4}{25} = rac{860}{625} = 1,376$$

Задание 2. Найдите значение выражения

1. $$9,3 + 7,8 = 17,1$$
2. $$8,7 + 4,6 = 13,3$$
3. $$6,9 + 7,4 = 14,3$$
4. $$5,7 - 7,6 = -1,9$$
5. $$4,9 - 9,4 = -4,5$$
6. $$6,1 - 2,5 = 3,6$$
7. $$5,2 - 3,1 = 2,1$$
8. $$2,1 - 9,6 = -7,5$$
9. $$8,9 - 4,3 = 4,6$$