(1+0.228-0.21)×(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)×(0.228-0.21)
问题描述:
(1+0.228-0.21)×(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)×(0.228-0.21)
简便运算,要写出具体过程
答
设1+0.228-0.21=x 0.228-0.21=y
原式=x*(y+0.2003)-(x+0.2003)*y
=xy+0.2003x-xy-0.2003y
=0.2003x-0.2003y
=0.2003*(x-y)
=0.2003*1
=0.2003用数学方法哩!实际上面的就是代数方法(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+0.228-0.21-0.228+0.21)×0.223=1×0.2003=0.2003