25x方-121x=0-搜答案-搜狗做题网

若X方-2XY+Y方+1XY-11=0则：x-y=0.而且xy=1所以,x=y=1,或者,x=y=-1所以,x/y=1X方+6XY+9Y方分之X方-25Y方*5X-25Y分之X+3Y=（x²

X^2=25,X=±5,X^2-81=0X^2=81,X=±925X^2=36X^2=36/25X=±6/5.

X^2+6X+9+Y^2-8Y+16=0所以（X+3）^2+(Y-4)^2=0所以X=-3,Y=4所以(X+Y)^2-(X-Y)^2=4XY=4*4*(-3)=-48

因为3x方+xy-2y方=0,即（x+y)(3x-2y)=0,而x+y≠0,所以3x-2y=0原式=[（x+y)^2-4xy]/[(x+3y)(x-y)/(x+3y)(x-3y)=(x-3y)/(x+

答：x^2-x-1=0显然x不为0,两边同除以x得：x-1-1/x=0x-1/x=1两边平方得：x^2-2+1/x^2=1x^2+1/x^2=3

321我爱你·：25x²-121=0(5x)²-11²=0(5x+11)(5x-11)=0∴5x+11=0或5x-11=0∴x1=-11/5或x2=11/5

x三次方+3x²-10x=0

x三次方+3x²-10x=X(X^2+3X-10)=X(X+5)(X-2)=0X1=0X2=-5X3=2

把X方—3X+1=0两边除以X得X-3+x分之一=0,x+x分之一=3,变成x方分之一+2+x方=3,变成x方分之一+x方=1,

x方-5x+1=0两边除以x得∴x-5+1/x=0x+1/x=5两边平方得x²+2+1/x²=25x²+1/x²=23

X²+2009²X+2008×2010=0△=2009^4-4×2008×2010∴√△=4036079∴X1=(-2009²-4036079)/2=-4036080X2

x²-2x+3=0x²-2x=-3所以原式=2(x²-2x)-20=-6-20=-26

(x-1)(x-12)=0　x=1或12（5x+2)(x-3)=0　　x=3或-2/5要给分哦

（1）x²+x=0x(x+1)=0x1=0x2=-1(2)x²-2√3x=0x(x-2√3)=0x1=0x2=2√3(3)4x²-121=0(2x+11)(2x-11)=

如果方程是x*x-6*x-6-x*sqrt(x*x-2*x-2)=0解得：x=9/5-3/5*19^(1/2)

x²+x+1=0x+1+1/x=0x+1/x=-1两边平方得x²+2+1/x²=1x²+1/x²=-1两边平方得x^4+2+1/x^4=1x^4+1/

x^2+3x+1=0x^2+1/x^2=((-3x-1)^1+1)/(-3x-1)=(9x^2+6x+2)/(-3x-1)=(-27x-9+6x+2)/(-3x-1)=7x^4+1/x^4=(x^2+

已知x方-4x+4+|y+x|=0,===>(X-2)^2+ly+xl=0====>x=2,y=-2,代入求解即可.（平方数>=0,绝对值>=0)再问：我问一下你的======是什么意思？你能帮我把过

1、2x²-x=0x(2x-1)=0∴x=0x=1/22、x²-x/2=1x²-x/2+1/16=17/16(x-1/4)²=17/16∴x=1/4+√17/4

原式变成:1+x+x^2+……+x^2009=(1+x+x^2)+x^3(1+x+x^2)+……+x^2007（1+x+x^2）=0