先化简，再求值：(1/（x+1）+（x^2-2x+1）/（x^2-1)/（x-1）/（x+1）,其中x=3

显示全部楼层 · 2013-1-9 22:04:39

1/（x+1）+（x^2-2x+1）/（x^2-1)/（x-1）/（x+1）=1/(x+1)+(x-1)2/(x+1)(x-1)×(x+1)/(x-1)=1/(x+1)+1=(x+2)/(x+1)当x=3时原式=5/4[1/（x+1）+（x^2-2x+1）/（x^2-1)]/（x-1）/（x+1）=[1/(x+1)+(x-1)2/(x+1)(x-1)]×(x+1)/(x-1)=1/(x-1)+1当x=3时原式=1/2+1=3/2...

千问 · 2013-1-9 22:04:39

你给的题就不明白,用手机把原题拍下来,补充到后面.这题这么简单,唉........检验正确答案你就直接代入,就知道了.式子本身就极为简单....

千问 · 2013-1-9 22:04:39

[1/(x+1)+(x^2-2x+1)(x^2-1)]/[(x-1)/(x+1)]=[1/(x+1)+(x-1)^2/(x-1)(x+1)]/[(x-1)/(x+1)]=[1/(x+1)+(x-1)/(x+1)]*(x+1)/(x-1)=1/(x+1)*(x+1)/(x-1)+(x-1)/(x+1)*(x+1)/(x-1)=1/(x-1)+1...