-8 4/7-(-6 3/5)-(9 2/5)-1,6-6 3/7

-8 4/7 + 6 3/5 - 9 2/5 - 1,6 - 6 3/7 = -8 4/7 + 6 3/5 - 9 2/5 - 1 6/10 - 6 3/7 = -8 4/7 + 6 3/5 - 9 2/5 - 1 3/5 - 6 3/7 = -8 20/35 + 6 21/35 - 9 14/35 - 1 21/35 - 6 15/35= -1 34/35 - 9 14/35 = -10 48/35 - 1 21/35 = -11 69/35 - 6 15/35 = - 17 84/35 = -19 14/35 = -19 2/5.