更新时间2018-03-19 19:02:35
(1)(1+0.23+0.34)X(0.23+0.34+0.65)-(1+0.23+0.34+0.65)X(0.23+0.34)
(2)(2.1+2.2+2.3)X(2.2+2.3+2.4)-(2.1+2.2+2.3+2.4)X(2.2+2.3)
①=(1+0.23+0.34)*(0.23+0.34+0.65)-(1+0.23+0.34)*(0.23+0.34)-0.65*(0.23+0.34)
=(1+0.23+0.34)*(0.23+0.34+0.65-0.23-0.34)-0.65*(0.23+0.34)
=(1+0.23+0.34)*0.65-0.65*(0.23+0.34)
=(1+0.23+0.34-0.23-0.34)*0.65
=1*0.65
=0.65
②=(2.1+2.2+2.3)*(2.2+2.3+2.4)-(2.1+2.2+2.3)*(2.2+2.3)-2.4*(2.2+2.3)
=(2.1+2.2+2.3)*(2.2+2.3+2.4-2.2-2.3)-2.4*(2.2+2.3)
=(2.1+2.2+2.3)*2.4-2.4*(2.2+2.3)
=(2.1+2.2+2.3-2.2-2.3)*2.4
=2.1*2.4
=5.04
设0.23+0.34为a,0.23+0.34+0.65为b
于是(1+0.23+0.34)X(0.23+0.34+0.65)-(1+0.23+0.34+0.65)X(0.23+0.34)=(1+a)Xb-(1+b)Xa
=b+ab-(a+ab)
=b+ab-a-ab
=b-a
b-a=,0.23+0.34+0.65-0.23+0.34=0.65
于是(1+0.23+0.34)X(0.23+0.34+0.65)-(1+0.23+0.34+0.65)X(0.23+0.34)=0.65
下一题同理,我不写了!打字好累!!我懒!!!
1)原式=(1+0.23+0.34)(0.23+0.34)+(1+0.23+0.34)×0.65-(1+0.23+0.34)(0.23+0.34)-0.65×(0.23+0.34)
=0.65×(1+0.23+0.34-0.23-0.34)
=0.65×1
=0.65
2)原式=(2.1+2.2+2.3)×(2.2+2.3)+(2.1+2.2+2.3)×2.4-(2.1+2.2+2.3)×(2.2+2.3)-2.4×(2.2+2.3)
=2.4×(2.1+2.2+2.3-2.2-2.3)
=2.4×2.1
=5.04