已知x不等于y,且x²-x=3,y²-y=3,求代数式x² xy y²的值-搜答案-智慧作业帮

(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

67/78,令3x=4y=5z=60k即可

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

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

x+y=03x+y分之7x+3y=?=2x+x+y分之4x+3x+3y=2x分之4x=2

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

x,y互为相反数∴x+y=0y/x=-1a,b互为倒数∴ab=1x-n/ab-（-y）+y/x=x+y-n/ab+y/x=0-3-1=-4

x-ab分之n-（-y）+x分之y=0-3-1=-4；

∵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

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

ay/(y-b)

(1)4x-3y-3z=0,(2)x-3y+z=0,(1)-(2)3x=4z;z=3/4x(1)+3(2)7x=12y;y=7/12x,x:y:z=12:7:9

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

因为,x-y=3xy所以：-3x+6xy+3y/[(7x-5y)-9xy-(3x-y)]=[-3(x-y)+6xy]/[(7x-5y)-9xy-(3x-y)]=[-3*3xy+6xy]/[7x-5y-

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/