317 Вычислите: a) -4,5 ; -0,9 в) 2,1 ; -6,3 д) 7,2. (-1,9) -5,70,8 ж) -1,25:1 9 16 и) 5 3 7 -1 5 14 б) -9,4; 4,7 -1,7 г); 8,5 e) 0,63 : (-7 9); з) -3,4:3 2 5; -1 1 к) 3 7 14 59

a)

\[\frac{-4.5}{-0.9} = \frac{4.5}{0.9} = \frac{45}{9} = 5\]

Ответ: 5

в)

\[\frac{2.1}{-6.3} = -\frac{2.1}{6.3} = -\frac{21}{63} = -\frac{1}{3}\]

Ответ: -1/3

д)

\[\frac{7.2 \cdot (-1.9)}{-5.7 \cdot 0.8} = \frac{7.2 \cdot 1.9}{5.7 \cdot 0.8} = \frac{72 \cdot 19}{57 \cdot 8} = \frac{9 \cdot 19}{57} = \frac{171}{57} = 3\]

Ответ: 3

ж)

\[-1.25 : 1\frac{9}{16} = -1\frac{1}{4} : \frac{25}{16} = -\frac{5}{4} : \frac{25}{16} = -\frac{5}{4} \cdot \frac{16}{25} = -\frac{1}{1} \cdot \frac{4}{5} = -\frac{4}{5}\]

Ответ: -4/5

и)

\[\frac{5\frac{3}{7}}{-1\frac{5}{14}} = \frac{\frac{38}{7}}{-\frac{19}{14}} = \frac{38}{7} : \left(-\frac{19}{14}\right) = \frac{38}{7} \cdot \left(-\frac{14}{19}\right) = \frac{2}{1} \cdot (-2) = -4\]

Ответ: -4

б)

\[\frac{-9.4}{4.7} = -\frac{9.4}{4.7} = -\frac{94}{47} = -2\]

Ответ: -2

г)

\[\frac{-1.7}{8.5} = -\frac{1.7}{8.5} = -\frac{17}{85} = -\frac{1}{5}\]

Ответ: -1/5

e)

\[0.63 : \left(-\frac{7}{9}\right) = \frac{63}{100} : \left(-\frac{7}{9}\right) = \frac{63}{100} \cdot \left(-\frac{9}{7}\right) = \frac{9}{100} \cdot (-9) = -\frac{81}{100} = -0.81\]

Ответ: -0.81

з)

\[-3.4 : 3\frac{2}{5} = -3.4 : \frac{17}{5} = -\frac{34}{10} : \frac{17}{5} = -\frac{17}{5} : \frac{17}{5} = -\frac{17}{5} \cdot \frac{5}{17} = -1\]

Ответ: -1

к)

\[\frac{-1\frac{1}{7}}{3\frac{1}{14}} = \frac{-\frac{8}{7}}{\frac{43}{14}} = -\frac{8}{7} : \frac{43}{14} = -\frac{8}{7} \cdot \frac{14}{43} = -\frac{8}{1} \cdot \frac{2}{43} = -\frac{16}{43}\]

Ответ: -16/43