精品偷拍一区二区三区,亚洲精品永久 码,亚洲综合日韩精品欧美国产,亚洲国产日韩a在线亚洲

  • <center id="usuqs"></center>
  • 
    
  • 先化簡代數(shù)式再求值(3/x+1 - x+1)÷x²-2x/x+1,其中x滿足方程x/x-1+1/x=1

    先化簡代數(shù)式再求值(3/x+1 - x+1)÷x²-2x/x+1,其中x滿足方程x/x-1+1/x=1
    數(shù)學(xué)人氣:773 ℃時(shí)間:2019-11-04 07:53:37
    優(yōu)質(zhì)解答
    =[3/(x+1)-(x-1)]÷(x²-2x)/(x+1)
    =[3/(x+1)-(x-1)(x+1)/(x+1)]÷x(x-2)/(x+1)
    =[3-(x+1)(x-1)]/(x+1)÷x(x-2)/(x+1)
    =[3-x²+1)]/(x+1)÷x(x-2)/(x+1)
    =(4-x²)/(x+1)/(x+1)÷x(x-2)/(x+1)
    =(2+x)(2-x)/(x+1)x(x-2)/(x+1)
    =-(x+2)(x-2)/(x+1)*(x+1)/x(x-2)
    =-(x+2)/x

    x/(x-1) + 1/x = 1
    (x² + x-1) / x(x-1)=1
    x² + x-1 = x(x-1)
    x² + x-1 = x² -x
    2x=1
    x = 1/2
    (3/x+1 - x+1)÷x²-2x/x+1
    =-(x+2)/x
    =-(1/2+2)÷1/2
    =-5/2*2
    =-5
    我來回答
    類似推薦
    請使用1024x768 IE6.0或更高版本瀏覽器瀏覽本站點(diǎn),以保證最佳閱讀效果。本頁提供作業(yè)小助手,一起搜作業(yè)以及作業(yè)好幫手最新版!
    版權(quán)所有 CopyRight © 2012-2024 作業(yè)小助手 All Rights Reserved. 手機(jī)版