已知,x y=5,xy=6,则x的平方减Y的平方=-搜答案-大师作文网

-xy（x^2y^5-xy^3-y)=-(xy^2)^3+(xy^2)^2+xy^2=-(-2)^3+4-2=8+4-2=10

x^2y+xy^2=xy(x+y)=1/5

5xy+4x+7y+6x-3xy-4xy+3y=5xy-3xy-4xy+4x+6x+7y+3y=（5-3-4）xy+（4+6）x+（7+3）y=-2xy+10x+10y=-2xy+10（x+y）因为x

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×(

x²y+xy²=xy(x+y)=10

“x愚人国度”您好,很高兴为您解答!x^2y+xy^2=xy(x+y)=-3*6=-18

x^2y+xy^2=xy(x+y)=-3*6=-18

x^2y+xy^2=xy(x+y)=(-3)×5=-15

x+y=5,xy=-3,则x^2y+xy^2=xy(x+y)=-3*5=-15

先把代数式（5XY+4X+7Y)+(6X-3XY)-(4XY-3Y)化简（5XY+4X+7Y)+(6X-3XY)-(4XY-3Y)=5XY+4X+7Y+6X-3XY-4XY+3Y=-2XY+10X+1

已知x-y=6,xy=-2,求3（xy+x-2y）-5(y-2x)+2(xy-x)的值.=3xy+3x-6y-5y+10x+2xy-2x=5xy+11x-11y=5×(-2)+11×6=-10+66=

∵x-y=4xy，∴2x+3xy-2yx-2xy-y=2(x-y)+3xyx-y-2xy=8xy+3xy4xy-2xy=112．故答案为：112．

因为xy/（x+y）=1/2所以x+y=2xy原式=3（x+y)-5xy/(-x-y+3xy)=3*2xy-5xy/(-2xy+3xy)=xy/xy=1

-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

yx+xy=x2+y2xy=(x+y)2-2xyxy当x+y=2，xy=-5时，原式=22-2×(-5)-5=-145．故答案为-145．

∵A=8x²y-6xy²-3xy,B=7xy²-2xy+5x²y　∴C=3（A+B)　　=3(8x²y-6xy²-3xy+7xy²

3(x^2-xy)-xy+y^2=3(x^2-xy)-(xy-y^2)=3*5-(-3)=15+3=18

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-

原式=-xy²（x²y^4-xy²-1）∵xy²=-2原式=2（（-2)²-（-2）-1）=10