先化简再求值(x-1)² x(x 2),其中x=根号2-搜答案-搜狗做题网

1+(2x-4)/(x^2-a-2)]/[(x+3)/(x^2-1)]={1+2(x-2)/[(x-2)(x+1)]}(x^2-1)/(x+3)=[1+2/(x+1)](x+1)(x-1)/(x+3)

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：

（3x/x-1-x/x+1)*x^2-1/2x,其中x=-3=(3x^2+3x-x^2+1)/(x-1)(x+1)*(x+1)(x-1)/2x=(2x^2+x+1)/2x=x+1/2+1/2x=-3+

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

3x^3-[-x^2-2(x-x^6)]=3x^3+x^2+2(x-x^6)=3x^3+x^2+2x-2x^6x=-1原式=-3+1-2-2=-6

(x+2-12/x-2)/(4-x)/(x-2),其中x=-1/2=(x²-4-12)(x-2)÷(4-x)/(x-2)=(x²-16)/(4-x)=-(4-x)(4+x)/(4-

求值：（1）若x

（1）由x12+x−12＝3⇒x+x−1＝7⇒x2+x−2＝47又由x32+x−32＝(x12+x−12)[(x+x−1)−1]⇒x32+x−32＝18代入原式即得原式=13（2）由lgx+lgy=2

【先化简再求值】（x-1）分之x÷【(1-x分之1）-1-x】=（x-1）分之x÷（x^2/(1-x)）=-1/xx=1时,原式无意义,x=2时,原式=-1/2,x=0时,原式无意义【选择题】下列约分

你好[（x-1）/x-（x-2）/（x+1）]/[（2x²-x）/（x²+2x+1）]={[（x-1）（x+1）-（x-2）x]/x（x+1）}/{x（2x-1）/（x+1）

(1x+2−1)÷x2+2x+1x2−4=−x−1x+2•(x+2)(x−2)(x+1)2=-x−2x+1，当x=tan60°-1=3-1时，原式=-3−1−23−1+1=-3−33=3-1．

（1x2+4x+4+1x2+2x）÷x+1x+2=[1(x+2)2+1x(x+2)]×x+2x+1=2(x+1)x(x+2)2×x+2x+1=2x(x+2)，当x=3时，原式=23×(3+2)=215

再答：希望能帮到您！还望采纳谢谢亲

x²-3x+2=(x-1)(x-2)=0x=1,x=2x=1,分母x²-2x+1=0,舍去所以x=2原式=[x(x-1)/(x+1)][(x+1)(x-1)/(x-1)²

原式=2x+1÷4x(x+1)=2x+1×x(x+1)4=x2，当x=-2时，原式=-22=-1．

(x-4)(x-2)-(x-1)(x-3)=x²-6x+8-x²+4x-3=-2x+5当x=-5/2时原式=-2*(-5/2)+5=5+5=10

22224x+4x+1-(4x-1)=4x+4x+1-4x+1=4x+2带入x=-2得4x+2=-6

2x²-4x/x+2·x²+2x/x²-4x+4+4x/2-x=2x(x-2)/(x+2)×x(x+2)/(x-2)²-4x/(x-2)=2x²/(x