解：4.05-2.05×1.4=4.05-(2+0.05)×1.4=4.05-2×1.4-0.05×1.4=4.05-2.8-0.07=1.18
4.05+37.85＝4+0.05+37+0.85＝（4+37）+（0.05+0.85）＝41+0.9＝41.9
