若5x-6y=0,且xy≠0,则 (5x-4y) (5x-3y)的值等于( )
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![若5x-6y=0,且xy≠0,则 (5x-4y) (5x-3y)的值等于( )](/uploads/image/f/6961180-4-0.jpg?t=%E8%8B%A55x-6y%3D0%2C%E4%B8%94xy%E2%89%A00%2C%E5%88%99+%285x-4y%29+%285x-3y%29%E7%9A%84%E5%80%BC%E7%AD%89%E4%BA%8E%28+%29)
5x-6y=05x=6y所以10x=12y所以原式=(12y-4y)/(12y-3y)=8y/9y=8/9
x-5xy+6y=0(√x-2√y)(√x-3√y)=0所以√x=2√y,√x=3√yx=4y或x=9y原式=(8y)/(9y)=8/9或=(14y)/(20y)=7/10
∵x-y=6,xy=4∴(x-y)²=36∴x²-2xy+y²=36∴x²+y²=36+2×4=44两边除以xyx/y+y/x=44/4=11∴xy^
由题设可知y=xy-1,∴x=yx3y=x4y-1,∴4y-1=1,故y=12,∴12x=x,解得x=4,于是x+y=4+12=92.故答案为:92.
题目不很清楚哈,我理解是:已知:x-(xy)^0.5-2y=0;求:(2x-(xy)^0.5)/(y+2*(xy)^0.5);由已知:(x/y)-(x/y)^0.5-2=0;[(X/y)^0.5-2]
2x+y=0y=-2x所以(y²-xy)/(x²+2xy)=(4x²+2x²)/(x²-4x²)=6x²/(-3x²)=
是不是x-5√xy-6y=0?(√x-6√y)(√x+√y)=0x>0,y>0则√x+√y>0所以√x-6√y=0√x=6√yx=36y所以√xy=6y所以原式=(36y-12y+y)/(36y+6y
3x²+3xy=03x²=-3xy因为x不等于0所以x=-y所以x:y=1:-1
x^2-xy-2y^2=0(x-2y)(x+y)=0x=2y或x=-y(x^2-2xy-5y^2)/(x^2+2xy+5y^2)=(x^2-xy-2y^2-xy-3y^2)/(x^2-xy-2y^2+
√x(√x+√y)=3√y(√x+5√y)x+√xy=3√xy+15yx-2√xy-15y=0(√x+3√y)(√x-5√y)=0∵√x+3√y>0∴√x=5√yt=x/y=25(2x+2√xy+3y
x-√(xy)-2y=(√x-2√y)(√x+√y)=0因为x>0,y>0所以√x+√y>0所以√x=2√yx=4y2x=8y,√(xy)=2√y*√y=2y原式=(8y-2y)÷(y+4y)=6y/
-2x+6xy-2y/(7x+5y)-9xy-(3x+y)=[3(x+y)-x-y]/[7x+5y-9/2(x+y)-3x-y]=2(x+y)/[-1/2(x+y)]=-4
(x+y)(x²-xy-y²)=0,=>x^3-y^3=0,x=y(x²-2xy-5y²)/(x²+2xy+5y²)=-6/8=-3/4=-
因为x>0,y>0,所以将x-根号xy-2y=0因式分解得(根号x-2根号y)(根号x+根号y)=0所以根号x=2根号y,即x=4y后面请自己代入吧,我看不懂你的表述.不好意思了
x²-4xy+4y²=0(x-2y)²=0则x=2y,因为xy≠0,则x≠0且y≠=0那么(x-y)/(x+y)=(2y-y)/(2y+y)=y/(3y)=1/3
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+xy-6y^2=0化简得(x-2y)(x+3y)=0x=2y或x=-3y分别带入2x^2-3xy+y^2/5x^2-7xy+2y^2化简即可.