化简再求值 X-2 -X 2分之5其中X=根号2-3-搜答案-大师作文网

原式=-x-2，当x=12时，原式=-12-2=-212．

你可以把这式子化简了挺简单的化简完就发现X都约掉啦式子是个定值所以X怎么变值都不变看错也没事什么公式?这题就得动笔算啊

原式=[1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)(x+4)]×(x+4)(x+5)=[1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)+1/(x+3)-1/(x

:(1)2x2-5x+x2+4x,其中x=-3=3x²-x=3x(-3)²+3=27+3=30(2)(3x2-xy-2y2)-2(x2+xy-2y2),其中x=6,y=-1=3x&

1.原式=【x的平方-x/4-2]÷（x+1/2)(x-1/2)=[9+3/4-2]÷【（-2.5）×（-3.5）】=31/4÷35/4=31/352.负数的平方与相反数的平方,结果相同.3.原式=(

原式=3x2+2x2-3x+4x-5x2=x，当x=2010时，原式=2010．

原式=[3x/(x-1)-2x/(x+1)]*(x+1)(x-1)/x=3x/(x-1)*(x+1)(x-1)/x-2x/(x+1)*(x+1)(x-1)/x=3(x+1)-2(x-1)=3x+3-2

,(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)/

x²+2x+1=10（x+1)²=10x+1=3或x+1=-3所以x=2或x=-4【（x²+4)/x-4】÷【（x²-4)/(x²+2x)】=【（x&

x3+2x2+x-1=（x2+2x+1）x-1=（（x+2）x+1）x-1，故答案为：（（x+2）x+1）x-1．

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

原式=(x-1)(x+1)/(x+2)*(x+2)/x-1=x+1然后代入数值即可很高兴为您解答,【学习宝典】团队为您答题.请点击下面的【选为满意回答】按钮,

(x^2-2x+1)/(x^2-1)+1/(x+1)=(x-1)^2/(x+1)(x-1)+1/(x+1)=(x-1)/(x+1)+1/(x+1)=x/(x+1)=1-根2分之一

原式=（-x2+5x+4）+（5x-4+2x2）=-x2+5x+4+5x-4+2x2=x2+10x=x（x+10）．∵x=-2，∴原式=-16．

{1-x/(x-1)}÷1/x(x-1)=(x-1-x)/(x-1)÷1/x(x-1)=-1/(x-1)÷1/x(x-1)=-x

[(x-4)/(x^2-1)]÷[(x^2-3x-4)/(x^2+2x+1)]+1/(x-1)=[(x-4)/(x-1)(x+1)]÷[(x+1)(x-4)/(x+1)^2]+1/(x-1)=[(x-

详细而规范的解答过程看图,明白就采纳,

原式=5x2-3x+2（2x-3）-7x2=5x2-3x+4x-6-7x2=-2x2+x-6，当x=12时，原式=-2×(12)2+12-6=-12+12-6=-6．

原式=(x+1)/(x+1)²×x(x-1)/[-2(x-1)]=-1/(x+1)×x/2=-x/2(x+1)当x=√2时原式=-√2/2(√2+1)=-√2(√2-1)/2=(√2-2)/

（x-2-x+2分之5）÷2x+4分之x-3=（x-2-x+5/2）÷2x＋x/4-3=1/2÷2x＋x/4-3=1/4x＋x/4-3