1. Выполните действие: a) 4,6-(-2,5); б)-25,344: (-3,6); в)-1\frac{1}{7}\cdot1\frac{5}{16}; г) 1\frac{1}{8}:(-3\frac{3}{8}).

Решение:

a) 4,6 \(\cdot\) (-2,5) = - (4,6 \(\cdot\) 2,5) = -11,5

4,6

\(\times\)

2,5

230

\underline{92}

11,50

б) -25,344 : (-3,6) = 25,344 : 3,6 = 7,04

  25,344|3,6
-25 2   |7,04
 ______
    1 44
  -  1 44
  ______
       0

в) -1\frac{1}{7} \(\cdot\) 1\frac{5}{16} = - \frac{8}{7} \(\cdot\) \frac{21}{16} = -\frac{8 \(\cdot\) 21}{7 \(\cdot\) 16} = -\frac{1 \(\cdot\) 3}{1 \(\cdot\) 2} = -\frac{3}{2} = -1,5

г) 1\frac{1}{8} : (-3\frac{3}{8}) = \frac{9}{8} : (-\frac{27}{8}) = \frac{9}{8} \(\cdot\) (-\frac{8}{27}) = -\frac{9 \(\cdot\) 8}{8 \(\cdot\) 27} = -\frac{1}{3} = -0,(3) \(\approx\) -0,33