α) 24⋅(-8) 61-64. (-7) 6)-2013 2)-3/4・(-18) g) 3,8-1-4,3)-12,6-(-0,8) 2) (-5,34+5,27). (3,8-6) 5 *)等.1-3)-(-34).壽 3) (47-78). (220-0,45)

а) 24 ⋅ (-8)

24 ⋅ (-8) = -192

б) -6,4 ⋅ (-7)

-6,4 ⋅ (-7) = 44,8

в) -2 3/8 ⋅ 1 3/5

Преобразуем смешанные числа в неправильные дроби:

-2 3/8 = - (2 ⋅ 8 + 3) / 8 = -19/8

1 3/5 = (1 ⋅ 5 + 3) / 5 = 8/5

-19/8 ⋅ 8/5 = -19/5 = -3 4/5

г) -3 6/7 ⋅ (-1 5/9)

Преобразуем смешанные числа в неправильные дроби:

-3 6/7 = - (3 ⋅ 7 + 6) / 7 = -27/7

-1 5/9 = - (1 ⋅ 9 + 5) / 9 = -14/9

-27/7 ⋅ (-14/9) = (27 ⋅ 14) / (7 ⋅ 9) = (3 ⋅ 2) / 1 = 6

д) 3,8 ⋅ (-4,3) - 12,6 ⋅ (-0,8)

3,8 ⋅ (-4,3) = -16,34

12,6 ⋅ (-0,8) = -10,08

-16,34 - (-10,08) = -16,34 + 10,08 = -6,26

е) (-5,34 + 5,27) ⋅ (3,8 - 6)

(-5,34 + 5,27) = -0,07

(3,8 - 6) = -2,2

-0,07 ⋅ (-2,2) = 0,154

ж) 4/9 ⋅ (-3 6/7) - (-3 1/7) ⋅ 5/58

Преобразуем смешанные числа в неправильные дроби:

-3 6/7 = - (3 ⋅ 7 + 6) / 7 = -27/7

-3 1/7 = - (3 ⋅ 7 + 1) / 7 = -22/7

4/9 ⋅ (-27/7) = - (4 ⋅ 27) / (9 ⋅ 7) = - (4 ⋅ 3) / 7 = -12/7 = -1 5/7

-22/7 ⋅ 5/58 = - (22 ⋅ 5) / (7 ⋅ 58) = - (11 ⋅ 5) / (7 ⋅ 29) = -55/203

-12/7 - (-55/203) = -12/7 + 55/203 = (-12 ⋅ 29 + 55) / 203 = (-348 + 55) / 203 = -293/203 = -1 90/203

з) (4 7/8 - 7 1/6) ⋅ (2 1/20 - 0,45)

Преобразуем смешанные числа в неправильные дроби:

4 7/8 = (4 ⋅ 8 + 7) / 8 = 39/8

7 1/6 = (7 ⋅ 6 + 1) / 6 = 43/6

2 1/20 = (2 ⋅ 20 + 1) / 20 = 41/20

39/8 - 43/6 = (39 ⋅ 3 - 43 ⋅ 4) / 24 = (117 - 172) / 24 = -55/24

41/20 - 0,45 = 41/20 - 45/100 = 41/20 - 9/20 = 32/20 = 8/5

-55/24 ⋅ 8/5 = - (55 ⋅ 8) / (24 ⋅ 5) = - (11 ⋅ 1) / (3 ⋅ 1) = -11/3 = -3 2/3