(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)

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(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)

(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)
(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)

(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)
设0.23+0.34=x
0.23+0.34+0.65=y
(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)
=(1+x)y-(1+y)x
=y+xy-x-xy
=y-x
=0.65

不用楼上那么麻烦!
设A=0.23+0.34
原式
=(1+A)*(A+0.65)-(1+A+0.65)*(A)
=A²+A+0.65A+0.65-A²-A-0.65A
=0.65

设:1+0.23+0.34=a; 0.23+0.34=b;
(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)
=a×(b+0.65)-(a+0.65)×b
=ab+0.65a-ab-0.65b
=0.65×(a-b)…………因为:a=1+0.23+0.34;b=0.23+0.34
=0.65×(1+0.23+0.34-0.23-0.34)
=0.65×1
=0.65