已知y不等于0, 比较(y^2 √2y 1)(y^2-√2y 1)

1,因为[(x^2+y^2)(x-y)]/[(x^2-y^2)(x+y)]=(x^2+y^2)/(x+y)^2,而(x+y)^2=x^2+y^2+2xy,因为x＜y＜0,所以2xy>0,所以(x+y)

2x^2-3xy+y^2=(2x-y)(x-y)=0则可得2x=y或x=y①当2x=y时把2x=y代入其中得x/y+y/x=x/2x+2x/x=1/2+2=2.5②当x=y时x/y+y/x=x/x+x

x²-5xy+6y²=0(x-2y)(x-3y)=0x=2y,x=3y所以x/y=2,x/y=3

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

y=2/xy=kx+12/x=kx+1kx^2+x-2=0因为总有公共点,即上式总有解,用判别式△=b^2-4ac>=01-4*k*(-2)>=08k>=-1k>=-1/8

x平方+2xy-8y平方=0(x+4y)(x-2y)=0x=-4y或x=2y(1)当x=-4y(x-y)/(x+y)=(-5)/(-3)=5/3(2)当x=2y(x-y)/(x+y)=1/3

loga(1/x)*loga(1/y)=loga(x)*loga(y)loga根号(y/x)*loga根号(x/y)=1/2*loga(y/x)*1/2*loga(x/y)=1/4[loga(y)-l

(1)由题意：ay+bx=xyxy-bx=ay(y-b)x=ay(b≠y)x=ay/(y-b)(2)由题意：kx=xy-9-mxxy-mx-kx=9x(y-m-k)=9x=9/(y-m-k)

已知x-y≠0,x²-x=7,y²-y=7,求x³+y³+x²y+xy²的值.经观察可知,x、y相当于是方程t²-t=7的两个不等

因为x^2+xy-2y^2=0所以x=-2yx=y(1)x=-2y所以x/y-y/x-(x^2+y^2)/xy=-2+1/2+5/2=1(2)x=yx/y-y/x-(x^2+y^2)/xy=1-1-2

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/X···这是什么意思···再问：x减y分之x等于x分之x减2y再答：两边同乘x（x-2y）再问：再答：题目是什么····就给个图啊···再问：如图，已知EFGH为矩形，AD⊥Bc于D，交HG于K，

x^2-2xy-4y^2=0x^2-2xy+y^2=5y^2(x-y)^2=5y^2(x-y)=正负根号5yx=y(1正负根号5)x/y=1正负根号5

x平方+xy-2y的平方=0,(x-y)(x+2y)=0x-y=0或x+2y=0x=y或x=-2yx/y-y/x-x的平方+y的平方/xy=(x²-y²-x²-y

你先设x/y=k,即x=yk所以原式=3k^2y^2+ky^2-4y^2=0即y^2(3k^2+k-4)=0因为y不能等于0,所以^2不等于0即3k^2+k-4=0得k=1(x不等于y,舍去）,K=-

如果是(x-y)/x=x/x-2y,则x:y=2:3(x-y)/x=（x-2y+2y）/x-2y1-y/x=1+2y/(x-2y)-y/x=2y/(x-2y)x/y=(x-2y)/-2yx/y=-1/

3x-2y=3y两边同时-y,得3x-3y=4y,左边因式分解得3(x-y)=4y,两边同除以3y,得(x-y)/y=4/3

(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

2x-3y=02x=3y3x/y=9/2所以(3x-2y)/y=9/2-2=5/2

无解