Пошаговое объяснение:

№1

(-2 1/3 - (-7 1/7)) + (7 3/7 + (-10 2/3)) =

(-2 1/3 + 7 1/7) + (7 3/7 - 10 2/3) =

-2 1/3 + 7 1/7 + 7 3/7 - 10 2/3 =

(-2 1/3 - 10 2/3) + (7 1/7 + 7 3/7) =

-12 3/3 + 7 4/7 = -13 + 7 4/7 =

-12 7/7 + 7 4/7 = -5 3/7

№2

-30 + 55 + (-15) - (-10) + 18 =

-30 + 55 - 15 + 10 + 18 =

(-30 + 10) + (55 - 15) + 18 =

-20 + 40 + 18 = 38

№3

1) 5 : 1/5 = 5 * 5/1 = 25/1 = 25

2) 3 : (-0,1) = -30

3) 25 + (-30) = 25 - 30 = -5

4) -5 + 17 = 12