已知x不等于y，且x^2-x=5

(x+y-z)/z=(y+z-x)/x=(z+x-y)/y[x+y]/z-1=[y+z]/x-1=[z+x]/y-1[x+y]/z=[y+z]/x=[z+x]/y设[x+y]/z=[y+z]/x=[z

x^2+根号2y=根号3,y^2+根号2x=根号3;两式相减；（x-y)(x+y-根号2)=0;x不等于y,x+y=根号2;两式相加：x^2+y^2+根号2(x+y)=2根号3;(x+y)^2-2xy

5x-4y=0;x=4y/5;x^2+y^2/x^2-y^2-x+y/x-y=（x²+y²-(x+y)²）/(x²-y²)=(x²+y

x+y=根号2x+根号2y=y+根号2xx-y+根号2y-根号2x=0(x+y)(x-y)+根号2（y-x)=0(x-y)(x+y-根号2)=0x+y=根号2

x/2=y/3=z/4=kx=2k,y=3k,z=4k2x+3y-4z/x+y+z=(4k+9k-16k)/(2k+3k+4k)=-1/3再问：确定？

已知x=y/3=z/5且x+y-2z不等于0那么y=3xz=5x（2x+3y-z）/（x+y-2z）=（2x+9x-5x）/（x+3x-10x）=6x/（-6x）=-1

4x-y+3z=0(1)2x+y+6z=0(2)()+(2)6x+9z=06x=-9zz/x=-2/3(1)*2-(2)8x-2y-2x-y=06x-3y=06x=3yx/y=1/2z/x=-2/3x

简单8x-(2x+y)=8x-2x-y=6x-yx>y6x>y6x-y>0所以8X>2X+y和m没有关系

x^2-x=2x^2-x-2=0(x-2)(x+1)=0x=2或x=-1同理,解得：y=2或y=-1x不等于y,所以x,y一个为-1,另一个为2x^2-xy+y^2=(-1)^2-(-1)*2+(2)

因为x+2y-z=0,7x-y-z=0两式相减,得：6x-3y=0,所以y=2x代入x+2y-z=0中,得：x+4x-z=0,那么z=5x那么(x+y+z)÷(2x-y-z)=(x+2x+5x)÷(2

∵X^2-X=3,Y^2-Y=3∴设k²-k-3=0,则x,y为这个方程的两个解xy=-3,x+y=1∴x²+y²=（x+y）²-2xy=1+6=7∴X^2+X

1.x^2-x=3,y^2-y=3∴x^2-x-3=0,y^2-y-3=0又∵x≠y∴x,y是方程z^2-z-3=0的两个不相等的根∴x+y=1,xy=-3∴x^2+xy+y^2=(x+y)^2-xy

3、A、B互为相反数正确,因为化简A=-2/（x+y）,B=2/(x+y);A+B=0

2X+3Y=3X-8Y=5Z解得X=11Z/5,Y=Z/5X+Y\X-Y=11Z/5+1/11-Z/5=2Z+1/11

依题意有f(0+0)+f(0-0)=2f(0)*f(0)又f(0)不等于0所以f(0)=1当x=0,y取任何实数时f(0+y)+f(0-y)=2f(0)*f(y)=2f(y)所以f(-y)=f(y)所

原方程化为（x+1）^2-(y-3)^2=0化简得|x+1|=|y-3|由于x+y≠2,所以x+1=y-3故x-y=-4

2x²-xy-3y²=0(x+y)(2x-3y)=0x=-y(舍去)或x=3y/2x/y=3/2x/y-x²/(x-y)=x/y-x²/(x²-2xy

无解

2x-3y=0,所以2x=3y,x=1.5y2x+y=3y+y=4yx-y=1.5y-y=0.5y代入下式,又因为x不等于y.得：2x+y除以x-y=4y÷0.5y=8

2x²-xy-3y²=0(x+y)(2x-3y)=0x=-y,2x=3yx≠-y所以y=(2/3)x原式=(x²+2/3*x²)/(2/3*x²-4/