已知x不等于y且x^2-x=3_y^2-y=3-搜答案-智慧作业帮

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

3x²-2xy-8y²=0两边同除y²得:3(x/y)²-2(x/y)-8=0(3x/y+4)(x/y-2)=0x/y=2或x/y=-4/3

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

因为xy不为0,所以3x^2-2xy-8y^2=0可以两边同时除以y^2,得3(x/y)^2-2(x/y)-8=0即(3x/y+4)(x/y-2)=0解得x/y=2或者x/y=-4/3希望有用.

3x²-2xy-8y²=0(x-2y)(3x+4y)=0x=2y或3x=-4yx/y=2或x/y=-4/3

2x-y+z=0上式两边同时除以x可得y/x-z/x=2标注为①x-2y+3z=0上式两边同时除以x刻碟2y/x-3z/x=1标注为②联解①与②可得y/x=5,z/x=3所以(x²+3y&#

∵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

2分之1或负4分之3

(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

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/