Ответ:\(3.8+12.17=15.97\).\(14.7-9.21=5.49\).\(3.7\cdot1.6=5.92\).\(12.6:5=2.52\).Ответ: 1) 15,97; 2) 5,49; 3) 5,92; 4) 2,52.