Пошаговое объяснение:

№1

1) -3,8 + 2 1/3 = -38/10 + 7/3 = -114/30 + 70/30 = -44/30 = -22/15

2) -22/15 * (-1 7/8) = 22/15 * 15/8 = 11/1 * 1/4 = 11/4 = 2 3/4

3) 4 1/6 : (-1 2/3) = 25/6 : (-5/3) = 25/6 * (-3/5) = 5/2 * (-1/1) = -5/2 = -2 1/2

4) 2 3/4 + (-2 1/2) = 2 3/4 - 2 1/2 = 2 3/4 - 2 2/4 = 1/4

№2

1) -2,5 - 1 5/6 = -25/10 - 11/6 = -75/30 - 55/30 = -130/30 = -13/3

2) -13/3 : 1 4/9 = -13/3 : 13/9 = -13/3 * 9/13 = -1/1 * 3/1 = -3/1 = -3

3) 3 5/9 * (-2 1/4) = 32/9 * (-9/4) = 8/1 * (-1/1) = -8/1 = -8

4) -3 - (-8) = -3 + 8 = 5

№3

1) -5/12 - 3/4 = -5/12 - 9/12 = -14/12 = -7/6

2) -7/6 : 2 1/3 = -7/6 : 7/3 = -7/6 * 3/7 = -1/2 * 1/1 = -1/2 = -0,5

3) 5 1/3 * 0,75 = 16/3 * 75/100 = 4/1 * 25/25 = 4 * 1 = 4

4) -0,5 + 4 = 3,5

№4

1) 3/4 - 1 7/8 = 6/8 - 1 7/8 = -1 1/8

2) -1 1/8 : 3/4 = -9/8 * 4/3 = -3/2 * 1/1 = -3/2

3) 3 1/9 * 3/7 = 28/9 * 3/7 = 4/3 * 1/1 = 4/3

4) -3/2 + 4/3 = -9/6 + 8/6 = -1/6