18.9*178.178+0.49-17.8*189.18
问题描述:
18.9*178.178+0.49-17.8*189.18
简算
答
=18.9*178.178+0.49-17.8*(189+0.18)
=18.9(178.178-178)+0.49-17.8*0.18
=18.9*0.178+0.49-17.8*0.18
=0.178*(18.9-18)+0.49
=0.178*0.9+0.49
=0.6502