Question

简便计算：(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34+0.65)*(0.23+0.34)

Answer 1

*——是乘号吗？如果是——
（1+0.23+0.34）x(0.23+0.34+0.65)-(1+0.23+0.32+0.65)x(0.23+0.34)
=(0.23+0.34)+0.65+(0.23+0.34)x(0.23+0.34+0.65)-(1+0.23+0.32+0.65)x(0.23+0.34)
=0.65+(0.23+0.34)x(1+0.23+0.34+0.65-1-0.23-0.32-0.65)
=0.65+0
=0.65
除此之外还有一种方法：
（1+0.23+0.34）x(0.23+0.34+0.65)-(1+0.23+0.32+0.65)x(0.23+0.34)
=（1+0.23+0.34）x(0.23+0.34+0.65)-（0.23+0.34）-(0.23+0.32+0.65)x(0.23+0.34)
=(0.23+0.34+0.65)x（1+0.23+0.34-0.23-0.34）-（0.23+0.34）
=0.23+0.34+0.65-0.23-0.34
=0.65
——希望帮到了你！

Answer 2

令A=0.23+0.34=0.57
原式=(1+A)*(A+0.65)-(1+A+0.65)*A
=A+A2+0.65A+0.65-A-A2-0.65A
=0.65

Answer 3

后面用乘法分配律得到
(0.23+0.34+0.65)*(0.23+0.34)+(0.23+0.34)
和前面得到
(0.23+0.34+0.65)*[1+0.23+0.34-(0.23+0.34)]-(0.23+0.34)
等于0.65

Answer 4

设 1+0.23+0.34=A

A*（A-1+0.65）-（A+0.65）（A-1）
=A*（A+0.65）-A-[（A+0.65）*A-（A+0.65）}
=A*（A+0.65）-A-（A+0.65）*A+（A+0.65）
=0.65

Answer 5

令，0.23+0.34+0.65=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)
=（1+b)×a-(1+a)×b
=a+ab-b-ab
=a-b
=0.23+0.34+0.65-（0.23+0.34）
=0.65