先化简,再求值(11-2/x)/x²-4x+4/x-4-x+4/x+2,其中x²+2x-15=0
先化简,再求值(11-2/x)/x²-4x+4/x-4-x+4/x+2,其中x²+2x-15=0
因为x²+2x-15=0
解得x=-5, or x=3
(1-2/x)÷(x²-4x+4)/(x-4)-(x+4)/(x+2)
=(x-2)/x ×(x-4)/(x-2)^2-(x+4)/(x+2)
=(x-4)/[x(x-2)]-(x+4)/(x+2)
当x=-5时,
(x-4)/[x(x-2)]-(x+4)/(x+2)
=-9/35-(-5+4)/(-5+2)
=-9/35-1/3
=-27/105-35/105
=-62/105
当x=3时,
(x-4)/[x(x-2)]-(x+4)/(x+2)
=(3-4)/(3×1)-(3+4)/(3+2)
=-1/3-7/5
=-5/15-21/15
=-26/15
=-1又11/15
先化简,再求值:4-x²/x²+4x+4÷x²-2x/2x+4 +2/x²+x,其中x满足x²=x
先分解因式:
得(2-x)(2+x)/(x+2)(x+2)*2(x+2)/x(x-2)+2/x(x+1)
=2/x(x+1)-2/x
=-2/(x+1)
由x²=x,得x=0,或者x=1
因为x=0时,原式的第二项分母为0,无意义,所以x=1.将x=1代入化简后的等式得原式=-1.
先化简,再求值。【(x²+4/x)-4】÷(x²-4/x²-4/x²+2x),其中x=-1 具体过程。。
等于7/9,不用化简吧
先化简,再求值:(3x/x-2-x/x+2)÷2x/x²-4,其中x=3
原式=[3x(x+2)-x(x-2)]/[(x+2)(x-2)]÷2x/(x²-4)
=(3x²+6x-x²+2x)/(x²-4)×(x²-4)/(2x)
=(2x²+8x)/(x²-4)×(x²-4)/(2x)
=x+4
=3+4
=7
先化简,再求值:1/x+2-(x²-4x+4/x²-x)除以(x+1-3/x-1)
原式=1/(x+2) - (x²-4x+4)/(x²-x) ÷ [ x+1 -3/(x-1) ]
=1/(x+2) -(x-2)²/[x(x-1)] ÷[ (x+1)(x-1)/(x-1) -3/(x-1) ]
=1/(x+2) -(x-2)²/[x(x-1)] ÷(x²-1-3)/(x-1)
=1/(x+2) -(x-2)²/[x(x-1)] ÷ (x²-4)/(x-1)
=1/(x+2) -(x-2)²/[x(x-1)] × (x-1)/[(x+2)(x-2)]
=1/(x+2) -(x-2)/[x(x+2)]
=x/[x(x+2)] -(x-2)/[x(x+2)]
=2/[x(x+2)]
=2/(x²+2x)
∵x²+2x-4=0
∴x²+2x=4
原式=2/4=1/2
先化简再求值 x²-2x/x÷(x-4/x) 其中x=3
x²-2x/x÷(x-4/x)
=x(x-2)/x×x/(x+2)(x-2)
=x/(x+2)
当x=3时 原式=3/(3+2)=3/5
(1+1/x-2)÷x²-2x+1/x²-4
=(x-1)/(x-2)×(x+2)(x-2)/(x-1)²
=(x+2)/(x-1)
当x=-5时
原式=-3/(-6)=1/2
[1+2x-4/(x+1)(x-2)]÷x+3/x²-1
=(x+3)/(x+1)×(x+1)(x-1)/(x+3)
=x-1
当x=6时
原式=6-1=5
先化简,再求值(3x/x-2+x/x+2)/(x/x²-4),其中x=-3
[3x/(x-2)+x/(x+2)]/[x/(x²-4)]
={[3x(x+2)+x(x-2)]/(x²-4)}/[x/(x²-4)]
=[(4x²+4x)/(x²-4)]/[x/(x²-4)]
=[4x(x+1)/(x²-4)]/[x/(x²-4)]
=4x+4
=4×(-3)+4
=-8
先化简,再求值:x²-4x+4/x²-2x÷(x-4/x),其中x是不等式组x+4>0,2x+5<1的整数解 急用
(x²-4x+4)/(x²-2x)÷(x-4/x)
=(x-2)²/[x(x-2)]÷[(x²-4)/x]
=[(x-2)/x]×{x/[(x-2)(x+2)]}
=1/(x+2)
不等式组
{x+4>0,
{2x+5<1
==>{x>-4,x<-2
==>-4<x<-2
∵x是整数
∴x=-3
∴原式=1/(-3+2)=-1
先化简再求值:(x²+2x-8/x³+2x²+x)÷{(x-2/x)·(x+4/x+1)}其中x=-4/5
原式
=(x+4)(x-2)/x(x+1)² ÷ (x-2)(x+5)/x(x+1)
=1/(x+1)
=1/(-4/5+1)
=1/(1/5)
=5
不明白,可以追问如有帮助,记得采纳,谢谢
祝学习进步!
先化简,再求值;(x-1/x²-1+1/x+1)÷4/x²+x,其中X=-2
你的表达有歧义,猜想为:
[(x-1)/(x²-1)+1/(x+1)]÷4/(x²+x)
=2/(x+1)*x(x+1)/4
=x/2
=-1