(1+0.228-0.21)*(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)*(0.228-0.21)巧算?写清思路
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(1+0.228-0.21)*(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)*(0.228-0.21)巧算?写清思路
(1+0.228-0.21)*(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)*(0.228-0.21)巧算?
写清思路
(1+0.228-0.21)*(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)*(0.228-0.21)巧算?写清思路
若设0.228-0.21=0.018=x
则(1+0.228-0.21)*(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)*(0.228-0.21)
=(1+x)(x+0.2003)-(1.2003+x)*x
=x+0.2003+x方+0.2003x-1.2003x-x方
=0.2003
设0.228-0.21=t
则:原式=(1+t)(t+0.2003)-t(1+t+0.2003)
=t(1+t)+(1+t)*0.2003t-t(1+t)-0.2003t
=0.2003
(1+0.228-0.21)×(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)×(0.228-0.21)
=(1+0.228-0.21)×(0.228-0.21)+(1+0.228-0.21)×0.2003-(1+0.228-0.21)×(0.228-0.21)-0.2003×(0.228-0.21)
=(1+0.228-0.21)×0.2003-0.2003×(0.228-0.21)
=1×0.2003+(0.228-0.21)×0.2003-0.2003×(0.228-0.21)
=0.2003