(1+0.228-0.21)x(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)x(0.228-0.21)

问题描述:

(1+0.228-0.21)x(0.228-0.21+0.2003)-(1+0.228-0.21+0.2003)x(0.228-0.21)

设0.228-0.21为a,0.228-0.21+0.2003为b.
(1+a)x(b)-(1+b)x(a)
=b+ab-a-ab
=b-a
=0.2003