18.9x178.178+0.49-17.8x189.189如何简算?

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 19:14:39

18.9x178.178+0.49-17.8x189.189如何简算?
18.9x178.178+0.49-17.8x189.189如何简算?

18.9x178.178+0.49-17.8x189.189如何简算?
18.9x178.178+0.49-17.8x189.189
=18.9*178*1.001+0.49-17.8*189*1.001
=18.9*17.8*10*1.001+0.49-17.8*18.9*10*1.001
=0.49

18.9x178.178+0.49-17.8x189.189
=189*178(0.1*1.001-0.1*1.001)+0.49
=0+0.49
=0.49