Найдите выражение:

1. (-2 3/14) + (-1 5/7) - (-19/21)

2. (2 3/14-1 5/7+19/21)

3. - (-4) : (-1 1/3)

4. (-3 1/9) + (1 5/12) - (-17/18)

5. (3 1/9-1 5/12+17/18)

6. - (-7) : (-1 1/6).

1. (-2 3/14) + (-1 5/7) - (-19/21) = - 31/14 - 12/7 + 19/21 = - 93/42 - 72/42 + 38/42 = - 165/42 + 38/42 = - 127/42 = - 3 ц 1/42

2. (2 3/14-1 5/7+19/21) = 31/14 - 12/7 + 19/21 = 93/42 - 72/42 + 38/42 = 59/42 = 1 ц 17/42

3. - (-4) : (-1 1/3) = 4 : (- 4/3) = 4 * (- 3/4) = - 3

4. (-3 1/9) + (1 5/12) - (-17/18) = - 28/9 + 17/12 + 17/18 = - 224/72 + 102/72 + 68/72 = - 54/72

5. (3 1/9-1 5/12+17/18) = 28/9 - 17/12 + 17/18 = 224/72 - 102/72 + 68/72 = 190/72 = 95/36 = 2 ц 23/36

6. - (-7) : (-1 1/6) = 7 : (- 7/6) = 7 * (- 6/7) = - 6