LARA6
春芽
共回答了9个问题采纳率:77.8% 举报
化简原式
=2x(x+5)/(x+2)²/[(x+1)-12/(x+2)]
=[2x(x+5)/(x+2)²]/﹛[(x+1)×(x+2)-12]/(x+2)﹜
=[2x(x+5)/(x+2)²]/[﹙x²+3x-10)/(x+2)]
=[2x(x+5)/(x+2)²]/[(x+5﹚×(x-2﹚/(x+2)]
=[2x(x+5)/(x+2)²]×﹛(x+2)/[(x+5﹚×(x-2﹚]﹜
=2x/[(x+2)×(x-2﹚]
=2x/﹙x²-4x﹚
由已知x-4/x=2√3可知x²-4x=2√3x
∴2x/﹙x²-4x﹚
=2x/2√3x
=1/√3
=√3/3
1年前
10