а)  - 3,2 * 1,7 = - 5,44.

б)  3 1/3 * ( - 2 2/7 ) = 10/3 * ( - 16/7 ) = - 160/21 = 7 13/21.

в)  1 2/3 : 5/6 = 5/3 : 5/6 = 5/3 * 6/5 = 30/15 = 2/1 = 2.