若xy≠0,3x-2y=0,则等于( )

由y=3xy+x得x-y=-3xy2x+5xy-2y/x-2xy-y=2（x-y）+5xy/x-y-2xy=-6xy+5xy/-3xy-2xy1/5

y-x-2xy=0y-x=2xyx-y=-2xy(3x+xy-3y)/(y-xy-x)=[3(x-y)+xy]/[(y-x)-xy]=(-6xy+xy)/(2xy-xy)=-5xy/xy=-5

原方程左边=（2x-y）（x+2y）=0所以x=y/2或x=-y/2将x的值分别代入到x+y/x-y得-3或-1/3

|2x+y+1|+√2y+3x=0,则每项等于0时,才成立2x+y+1=0（1）2y+3x=0（2）（1）*2-（2）x+2=0x=-2代入（1）解得y=3则xy=-6【数学辅导团】为您解答,如果本题

1、x-2√xy-3y=（√x-3√y)(√x+√y)=0解得√x=3√y或者√x=-√y（舍去）也就是x=9y2x+y+√xy除以y-x-√xy=(2*9y+y+3√y*√y)/(y-9y-3√y*

两边同时除以y的平方.3(x/y)^2+(x/y)-4=0[3(x/y)+4][(x/y)-1]=0x/y=-4/3,x/y=1

2x²-3xy+y²=(2x-y)(x-y)=02x-y=0或x-y=0x=y/2或x=yx/y+y/x=5/2或=2

3x²+3xy=03x²=-3xy因为x不等于0所以x=-y所以x：y=1：-1

y-x-2xy=0所以x-y=-2xyy-x=2xy所以原式=[3(x-y)+xy]\[(y-x)-xy]=[3×(-2xy)+xy]\(2xy-xy)=-5xy\xy=-5

2x^2-3xy+y^2=(x-y)*(2x-y)=0x=y,x/y+y/x=1+1=2或2x=y,x/y+y/x=1/2+2=5/2

x^2+2xy-3y^2=0x^2+2xy+y^2-4y^2=0(x+y)^2=4y^2x+y=2y或x+y=-2yx=y或x=-3y因为两个正实数所以x=yx^2+xy+y^2/x^2-xy+y^2

xy/(x+y)=2(x+y)/xy=1/21/x+1/y=1/2(3x-xy+3y)/(-x+3xy-y)=(3/y-1+3/x)/(-1/y+3-1/x)=[3(1/x+1/y)-1]/[(3-(

lg(xy)=0xy=1则:|x|＝1而Y=X,|x|不等于Y所以x=-1,y=-1原式=log8（2）=1/3

2x²-5xy-3y²=0(2x+y)(x-3y)=0所以y=-2x或x=3yy=-2x则x/y+y/x=-1/2-2=-5/2x=3yx/y+y/x=3+1/3=10/3选A

x+y=5xy（2x-3xy+2y)/(x+2xy+y）=[2（x+y）-3xy]/[(x+y)+2xy]=(2×5xy-3xy)/(5xy+2xy)=7xy/7xy=1再问：若x＋1/x＝3,求(x

1、分解因式得（x-y）(x-2y)=0∴ x=y或x=2y（1）x=y,则x/y+y/x=1+1=2（2）x=2y,则x/y+y/x=2+0.5=2.52、a0=-1（代入x=0即可）a5

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-

2X^2+3xy-2y^2=0(2x-y)(x+2y)=0即：2x-y=0或,x+2y=0y=2x或x=-2y当y=2x时：x+y/x-y=3x/(-x)=-3当x=-2y时：x+y/x-y=-y/(

∵x-y=4xy∴原式=[2(x-y)+3xy]/[-(x-y)-2xy]=(8xy+3xy)/(-4xy-2xy)=11xy/(-6xy)=-11/6

x^2+y^2=3xy两边平方x^4+2x^2y^2+y^4=9x^2y^2x^4+y^4=7x^2y^2两边除以x^2y^2x^2y^-2+x^-2y^2=7