Ответ:\(3.4\cdot6.2=21.08\), \(8.4:0.4=21\).\(285.7+21.08-21=285.78\).\(35.83+2.71=38.54\), \(38.54\cdot2.5=96.35\).\(100.35-96.35=4\).Ответ: 285,78; 4.