0.8*0.3*0.1+0.2*0.7*0.1+0.2*0.3*0.9+0.8*0.7*0.1+0.8*0.3*0.9+0.2*0.7*0.9+0.8*0.7*0.9=0.024+0.014+0.054+0.056+0. 216+0.126+0.50 4=0.038+0.110+0.342+0.504=0.148+0.846=0.994
№3
43 53 12
8 78 104
№4
20:4=5
12:4=3
1и13/19 выносим за скобку...
1и13/19(2и1/4+7/16-1и1/2)=1и13/19(9/4+7/16-3/2)=1и13/19*11/16=32/19*11/16=22/19=1и 3/19
7820•38=281520
706•304=214624