简算:19.99乘19.98-19.97乘19.96

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/05 00:55:03
简算:19.99乘19.98-19.97乘19.96

简算:19.99乘19.98-19.97乘19.96
简算:19.99乘19.98-19.97乘19.96

简算:19.99乘19.98-19.97乘19.96
19.99*19.98-19.97*19.96
=(19.97+0.02)*19.98-19.97*(19.98-0.02)
=(19.97*19.98+0.02*19.98)-(19.97*19.98-19.97*0.02)
=19.97*19.98+0.02*19.98-19.97*19.98+19.97*0.02
=0.02*19.98+19.97*0.02
=0.02*(19.98+19.97)
=0.02*(20-0.02+20-0.03)
=0.02*(40-0.05)
=0.02*40-0.02*0.05
=0.8-0.01
=0.799

你好!!!
(19.98+0.01)(19.98)-(19.98-0.01)(19.98+0.01)
=19.98×0.01+0.01×0.01
=0.01×19.99
=0.1999
还有什么不明白的地方再问我。
谢谢!!!

(20-0.01)*(20-0.02)-(20-0.03)*(20-0.04)
=400-0.4-0.2+0.0002-400+0.8+0.6-0.0012
=0.8+0.0002-0.0012
=0.799

(19.98+0.01)(19.98)-(19.98-0.01)(19.98+0.01)
=19.98×0.01+0.01×0.01
=0.01×19.99
=0.1999

19.99*19.98+19.98*19.97-19.98*19.97+19.97*19.96
=0.02*19.98-0.02*19.97=0.0002