1) 1/13 + (-5/18 - 1/13 + 12/17) - (12/17 - 5/18 + 7/5)
= 1/13 - 5/18 - 1/13 + 12/17 - 12/17 + 5/18 - 7/5
= (1/13 - 1/13) + (-5/18 + 5/18) + 12/17 - 7/5
= -59/85

2) 1/25 - 4/27 + (-23/27 + (-1/25) - 5/43) + 5/43 - 4/7
= 1/25 - 4/27 - 23/27 - 1/25 - 5/43 + 5/43 - 4/7
= (1/25 - 1/25) + (-5/43 + 5/43) - (4/27 + 23/27) - 4/7
= -1 - 4/7
= -11/7

3) 1/16 - 5/21 + (-1/16 + (-3/5) - (-5/21)) + (-2/5) + 3/4
= 1/16 - 5/21 - 1/16 - 3/5 + 5/21 - 2/5 + 3/4
= (1/16 - 1/16) + (-5/21 + 5/21) - (3/5 + 2/5) + 3/4
= -1 + 3/4
= -1/4

4) 46 . (1/2 - 7/23 - 27/46) : 1/5
= 46 . (-9/23) . 5
= 230 . (-9/23)
= -90

5) -34 . (1/17 - 5/34 + 1/2) : 4
= -34 . 7/17 . 1/4
= -14 . 1/4
= -7/2

6) (-2/3 + 3/7) : 4/5 + (-1/3 + 4/7) : 4/5
= (-2/3 + 3/7 - 1/3 + 4/7) : 4/5
= 0 : 4/5 = 0

7) (1(3/7) - 5/12) : 4/5 - (3/7 - 17/12) : 4/5
= (10/7 - 5/12 - 3/7 + 17/12) : 4/5
= 0 : 4/5 = 0

8) 29/19 . 49/51 + 29/19 . 34/51 - 29/19 . 32/51
= 29/19 . (49/51 + 34/51 - 32/51)
= 29/19 . 1 = 29/19