Умножение рациональных чисел Уровень В 1.--2 7 8 2.-6,08-0,7 3.-5,4-0,9 4. -4,8 (-3,2) 5.-0,8-1,2 15 6.-23 17 49 7.-25 5 24 12 8.--(-) 26 13 27 9. (-) 3 4 10. 49-(-)-(-2) 7 11.-2(-) 12. (-2)-(-) 36 13. (-) 14. 7,8 (-4,1) 15. -0,4-

Шаг 1: -4/7 * -2/8

\[-\frac{4}{7} \times -\frac{2}{8} = \frac{4 \times 2}{7 \times 8} = \frac{8}{56} = \frac{1}{7}\]

Шаг 2: -6,08 * 0,7

-6,08 * 0,7 = -4,256

Шаг 3: -5,4 * 0,9

-5,4 * 0,9 = -4,86

Шаг 4: -4,8 * (-3,2)

-4,8 * (-3,2) = 15,36

Шаг 5: -0,8 * 1,2

-0,8 * 1,2 = -0,96

Шаг 6: -2 3/17 * 15/49

\[-2\frac{3}{17} \times \frac{15}{49} = -\frac{37}{17} \times \frac{15}{49} = -\frac{37 \times 15}{17 \times 49} = -\frac{555}{833}\]

Шаг 7: -2 5/5 * 5/24

\[-2\frac{5}{5} \times \frac{5}{24} = -3 \times \frac{5}{24} = -\frac{3 \times 5}{24} = -\frac{15}{24} = -\frac{5}{8}\]

Шаг 8: -12/13 * (-26/27)

\[-\frac{12}{13} \times \left(-\frac{26}{27}\right) = \frac{12 \times 26}{13 \times 27} = \frac{312}{351} = \frac{8}{9}\]

Шаг 9: (-3/4)^2

\[\left(-\frac{3}{4}\right)^2 = \left(-\frac{3}{4}\right) \times \left(-\frac{3}{4}\right) = \frac{9}{16}\]

Шаг 10: 49 * (-1/7) * (-2)

\[49 \times \left(-\frac{1}{7}\right) \times (-2) = 49 \times \frac{2}{7} = \frac{49 \times 2}{7} = \frac{98}{7} = 14\]

Шаг 11: -2 2/5 * (-5/24)

\[-2\frac{2}{5} \times \left(-\frac{5}{24}\right) = -\frac{12}{5} \times \left(-\frac{5}{24}\right) = \frac{12 \times 5}{5 \times 24} = \frac{60}{120} = \frac{1}{2}\]

Шаг 12: (-2 2/3) * (-10/36)

\[\left(-2\frac{2}{3}\right) \times \left(-\frac{10}{36}\right) = \left(-\frac{8}{3}\right) \times \left(-\frac{10}{36}\right) = \frac{8 \times 10}{3 \times 36} = \frac{80}{108} = \frac{20}{27}\]

Шаг 13: (-1/4)^3

\[\left(-\frac{1}{4}\right)^3 = \left(-\frac{1}{4}\right) \times \left(-\frac{1}{4}\right) \times \left(-\frac{1}{4}\right) = -\frac{1}{64}\]

Шаг 14: 7,8 * (-4,1)

7,8 * (-4,1) = -31,98

Шаг 15: -0,4 * 1/5

\[-0.4 \times \frac{1}{5} = -0.4 \times 0.2 = -0.08\]