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. -2 3/14 + (-1 5/7) - (-19/21) = -2 3/14 - 1 5/7 + 19/21 = -2 9/42 - 1 30/42 + 38/42 =

= -3 39/42 + 38/42 = -3 1/42;

2. (2 3/14 - 1 5/7 + 19/21) = 2 9/42 - 1 30/42 + 38/42 = 1 51/42 - 1 30/42 + 38/42 =

= 21/42 + 38/42 = 59/42 = 1 17/42;

3. -(-4) / (-1 1/3) = 4 * (-3/4) = -12/4 = -3;

4. -3 1/9 + 1 5/12 - (-17/18) = -3 1/9 + 1 5/12 + 17/18 = -3 4/36 + 1 15/36 + 34/36 =

= -2 40/36 + 1 15/36 + 34/36 = -1 25/36 + 34/36 = -61/36 + 34/36 = -27/36 = -3/4; 

5. 3 1/9 - 1 5/12 + 17/18 = 3 4/36 - 1 15/36 + 34/36 = 2 40/36 -1 15/36 + 34/36 =

= 1 25/36 + 34/36 = 1 59/36 = 2 23/36;

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