先化简,再求值2x-4分之x方-4x 4

x减2y分之x减y除以x方减4xy加4y方分之x方减y方=[(x-y)/(x-2y)]×[(x-2y)²/(x+y)(x-y)]=(x-2y)/(x+y)=[(1+√2-2(1-√2)]/(

题目有误吧(x-x)x-1分之4(x-x)+(x-2)再问：(x方-x)(x-2)方再答：

[x/(x-2)-x/(x+2)]÷[4x/(x-2)]=[x(x+2)-x(x-2)]/[(x-2)(x+2)]×[(x-2)/4x]=4x/[(x-2)(x+2)]×[(x-2)/4x]=1/(x

原式=(x²-2x)/(x²-4)÷[x-2-(2x-4)/(x+2)]=x(x-2)/[(x-2)(x+2)]÷[(x-2)(x+2)/(x+2)-2(x-2)/(x+2)]=x

原式=[3x/(x--2)--x/(x+2)]*[(x^2--4)/x]=[3x(x+2)--x(x--2)]/(x^2--4)*[(x^2--4)/x]=(3x^2+6x--x^2+2x)/x=(2

x+4>0x>-42x+5

你写的看不懂分子分母的代数式用括号括起来否则分不出来先通分【（（x-2）(x+2)-x(x-1)）/x(x+2)(x+2)】(x+2)/(x-4)=(x-4)/x(x+2)(x-4)=1/x(x+2)

(x^2-2x)/(x^2-4)÷[(x-2)-(2x-4)/(x+2)]=x(x-2)/(x-2)(x+2)÷[(x-2)-(2x-4)/(x+2)]=x/(x+2)÷[(x-2)-(2x-4)/(

(4x²-4x+2分之x)*(2x²-x)=(4x²-7x/2)*(2x²-x)=(x/2)(8x-7)(x)(2x-1)=x^2(8x-7)(2x-1)/2,

[4(x²-x)+(x-2)²]/(x-1)=(4x²-4x+x²-4x+4)/(x-1)=(5x²-8x+4)/(x-1)=[5(x-1)²

化简结果：-X的3次方分之一乘以（5X方-4分之1乘以X+2分之1）

1x-2x(x-2)=---+--------÷--------x(3x-1)^23x-111=---+------÷xx3x-13x-11=--------+-------x(3x-1)x(3x-1

,(X-2-X+2分之5)/2x+4分之x-3=[(x-2)(x+2)-5]/(x+2)×2(x+2)/(x-3)=(x²-9)/(x+2)×2(x+2)/(x-3)=(x+3)(x-3)/

[3x/(x-1)-x/(x+1)]×(x²-1)/x=x[3(x+1)-(x-1)]/(x²-1)×(x²-1)/x=2x+4当x=√2-2时,原式=2x+4=2√2

原式＝[2x(x+2)-x(x-2)]/(x²-4)＋x/(x²-4)＝(x²+7x)/(x²-4)＝[x(x+7)]/[(x+2)(x-2)]代入x＝5原式＝

原式=2x-1-16+8x-16=10x-33将x=4/5代入上式得上式=4/5*10-33=-25

5x^3-10x^2+20x+8x^2-8x-5x^3+2x^2=12x代入得：12x=12*(-5/6)=-10

(x/(x-2)-x/(x+2))/(4x/(2-x))=(x(x+2-x+2)/(x-2)(2+2))/(4x/(2-x))=4x/(x-2)(x+2)/(4x/(2-x))=-1/(x+2)X=1

(x²+2x+1)分之(x+4)÷(x-2)分之x÷[x分之(x-2)×(x+1)分之(x+4)]=(x+1)²分之(x+4)×x分之(x-2)÷[x(x+1)]分之[(x-2)(

[2/（x+1)+4/（x²-1)]÷x/（x-1）=[(2/（x+1)+4/（x-1)（x+1）]÷x/（x-1）=[2（x-1）/（x+1)（x-1）+4/（x-1)（x+1）]÷x/（