Question

все на фото, даю 30 баллов

Answer 1

Ответ:

1)

$\frac{58}{5}$

2)

$\frac{5}{4}$

3)

$- 15.6$

4)

$\frac{7}{10}$

Пошаговое объяснение:

1)

$14 \frac{7}{15} - 3 \frac{23}{27} \times \frac{23}{27} - 1 \frac{1}{5} \times \frac{1}{6} = \\ = \frac{217}{15} - \frac{72}{23} \times \frac{23}{27} - \frac{6}{5} \times \frac{1}{6} = \\ = \frac{217}{15} - \frac{72}{27} - \frac{1}{5} = \\ = \frac{27 \times 217}{15 \times 27} - \frac{15 \times 72}{15 \times 27} - \frac{81 \times 1}{81 \times 5} = \\ = \frac{4859}{405} - \frac{1080}{405} - \frac{81}{405} = \\ = \frac{5859 - 1080 - 81}{405} = \frac{4698}{405} = \\ = \frac{81 \times 58}{81 \times 5} = \frac{58}{5}$

2)

$(5 \frac{8}{9} \div 1 \frac{17}{36} + 1 \frac{1}{4} ) \times \frac{5}{21} = \\ = ( \frac{53}{9} \div \frac{53}{36} + \frac{5}{4} ) \times \frac{5}{21} = \\ = ( \frac{53}{9} \times \frac{36}{53} + \frac{5}{4} ) \times \frac{5}{21} = \\ = ( \frac{36}{9} + \frac{5}{4} ) \times \frac{5}{21} = \\ = (4 + \frac{5}{4} ) \times \frac{5}{21} = \\ = ( \frac{4 \times 4 + 5 \times 1}{1 \times 4} ) \times \frac{5}{21} = \\ = ( \frac{16 + 5}{4} ) \times \frac{5}{21} = \frac{21}{4} \times \frac{5}{21} = \\ = \frac{5}{4}$

3)

$( - 3.25 - 2.75) \div \\ \div ( - 0.6) + 0.8 \times ( - 7) = \\ = - 6 \div 0.6 + 0.8 \times ( - 7) = \\ = - 10 - 5.6 = - 15.6$

4)

$( - 1 \frac{3}{8} - 2 \frac{5}{12} ) \div 5 \frac{5}{12} = \\ = ( - \frac{11}{8} - \frac{29}{12} ) \div \frac{65}{12} = \\ = ( \frac{ - 11 \times 12 - 29 \times 8}{8 \times 12} ) \times \frac{12}{65} = \\ = \frac{ - 132 - 232}{96} \times \frac{12}{65} = \\ = - \frac{364}{8} \times \frac{1}{65} = \\ = - \frac{364 \times 1}{8 \times 65} = - \frac{364}{520} = \\ = \frac{52 \times 7}{52 \times 10} = \frac{7}{10}$