Найдите значение выражений:1/5-1/4+1/3; 1/3-1/9+1/6; (2/3+1/9)-13/18; 3/4-1/2+7/8; 5/6-2/3+1/4; 1/3-(1/9+1/6).

1) 1/5 - 1/4 + 1/3 = 12/60 - 15/60 + 20/60 = (12 - 15 + 20) / 60 = 17/60;

2) 1/3 - 1/9 + 1/6 = 6/18 - 2/18 + 3/18 = (6 - 2 + 3) / 18 = 7/18;

3) (2/3 + 1/9) - 13/18 = (6/9 + 1/9) - 13/18 = 7/9 - 13/18 = 14/18 - 13/18 = (14 - 13) / 18 = 1/18;

4) 3/4 - 1/2 + 7/8 = 6/8 - 4/8 + 7/8 = (6 - 4 + 7) / 8 = 9/8 = 1 1/8;

5) 5/6 - 2/3 + 1/4 = 10/12 - 8/12 + 3/12 = (10 - 8 + 3) / 12 = 5/12;

6) 1/3 - (1/9 + 1/6) = 1/3 - (2/18 + 3/18) = 1/3 - 5/18 = 6/18 - 5/18 = (6 - 5) / 18 = 1/18.