1) 7\8 - ( -3\10) ; 7/8+3/10 = 35/40+12/40 = 47/40 = 1 7/40
4) -5\9 - (-3\4); -5/9 + 3/4 = -20/36 + 27/36 = 7/36
2) 11\12 - 17\18 = 33/36 - 34/36 = - 1/36
5) 3 11/12 - ( -4. 4\9); 3 11/12 + 4 4/9 = 3 33/36 + 4 16/36 = 7 49/36 = 8 13/36
3) -3\7 - 9\14 = -6/14 - 9/14 = -15/14 = - 1 1/14
6) 4 5\17 - 6 = 4 5/17 - 5 17/17 = -1 12/17