Question

(1+0.12+0.34)x(0.12+0.34+0.56)-(1+0.12+0.34+0.56)x(0.12+0.34)

要简便计算

Answer 1

(1+0.12+0.34)x(0.12+0.34+0.56)-(1+0.12+0.34+0.56)x(0.12+0.34)
=(0.34+0.56+0.12+0.34)x(0.12+0.34+0.56)-(1+0.12+0.34+0.56)x(0.12+0.34+0.56-0.56)
=0.34x(0.12+0.34+0.56)+(0.56+0.12+0.34)x(0.12+0.34+0.56)-(0.12+0.34)
-(0.12+0.34+0.56)x(0.12+0.34+0.56)+0.56x(0.12+0.34+0.56)
合并同类项，约去相同的式子

=（0.34+0.56）x（0.12+0.34+0.56）-0.12-0.34
=（0.12+0.34+0.56）-0.12-0.34
=0.56

Answer 2

减号前后的等式分别分拆为：
(1+0.12+0.34)*(0.12+0.34+0.56)
=(1+0.12+0.34)*(0.12+0.34)+(1+0.12+0.34)*0.56

(1+0.12+0.34+0.56)*(0.12+0.34)
=(1+0.12+0.34)*(0.12+0.34)+0.56*(0.12+0.34)

两个相减 等式简化为
(1+0.12+0.34)*0.56-0.56*(0.12+0.34)
=1*0.56+(0.12+0.34)*0.56-0.56*(0.12+0.34)
=0.56

最后得到答案 0.56