若xy≠1,5x2 2011x 9=0,9y2 2011y 5=0,求x y-搜答案-智慧作业帮

xy^5-xy等于多少

原式=xy(y^4-1)=xy(x²+1)(x²-1)=xy(x²+1)(x+1)(x-1)

-5x+2-3xy-5y因为xy=1所以原式=-5x-5y-1-5（x+y)-1因为x+y=3所以-15-1=-16

5x^2y/-1/2xy*3xy^2

5x^2y/-1/2xy*3xy^2=-7.5x²y²

1/x-1/y=(y-x)/xy=3所以y-x=3xyx-y=-3xy所以原式=[5(x-y)+3xy]/[3(x-y)-xy]=[5(-3xy)+3xy]/[3(-3xy)-xy]=-12xy/(-

解(x+1)平方+/y-1/=0∴x+1=0,y-1=0∴x=-1,y=1∴2(xy-5xy平方)-(3xy平方-xy)=(2xy+xy)+(-10xy平方-3xy平方)=3xy-13xy平方=3×(

1/x+1/y=2y+x=2xy(2x-xy+2y)=2(x+y)-xy=3xy(3x+5xy+3y)=3(x+y)+5xy=11xy(2x-xy+2y)÷(3x+5xy+3y)=3xy/11xy=3

(8xy-3x平方)-5xy-2(3xy-2x平方)=8xy-3x²-5xy-6xy+4x²=x²-3xy=4+6=10

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．

x=-1,y=-6或x=6,y=1代入式子得x^2-xy^2=37或30x^2y+xy^2=-42或42

1/x+1/y=5两边乘以xy得y+x=5xy∴x+y=5xy3x+4xy+3y/x+3xy+y=[3(x+y)+4xy]/[(x+y)+3xy]=(15xy+4xy)/(5xy+3xy)=19xy/

这个是原题要求的吧|x|/x+|y|/y+|xy|/xy（1）xy>0x,y都大于零或都小于零x,y都大于零时|x|/x+|y|/y+|xy|/xy=|x|/x+|y|/y+|xy|/xy=x/x+y

因为x+2y=0,所以x=-2y原式=(x^2+2xy)/(xy+y^2)=(4y^2-4Y^2)/(-3y^2+y^2)=0/(-2y^2)又因为xy不等于零,所以x、y君不等于零,所以-2y^2亦

1.先化简再求值（½x²y＋1／5xy²－¼xy)·(-½xy²),其中x=-2y=-½（½x²y＋1／5xy

根号下x+1+(y-5)²=0x+1=0,y-5=0x=-1,y=5所以x的y次方=（-1）的5次方=-1

1.若x+y=1,xy=-2,代数式（xy+5x-2y)-(-3xy+2x-5y)的值=xy+5x-2y+3xy-2x+5y=4xy+3x+3y=4*(-2)+3*1=-8+3=-52.已知一个长方形

解x²y-xy²=xy(x-y)=5×1=5a²b+ab²=1∴ab(a+b)=1∵a+b=3∴3ab=1∴ab=1/3再问：a(a-b)-a+b=?再答：=a

得y-x=3xyx-y=-3xy原式=-15xy+2xy/-3xy-4xy=-13/-7=13/7

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

-5X-5Y+3XY=-5(x+y)+3xy∵X+Y=3,XY=1∴原式=-15+3=-12

2xy-{5x-3[xy-1/3x(y+1)]-4xy}=2xy-{5x+x+3xy+xy-4xy}=-6x+3xy-xy