已知x y=5 xy=负3 求(4x-6y-2xy)-搜答案-智慧作业帮

xy/x+y=3则xy=3(x+y)2x-5xy+2y/x-3xy+y=2(x+y)-5xy/(x+y)-3xy=2(x+y)-15(x+y)/(x+y)-9(x+y)=-13(x+y)/-8(x+y

xy/x+y=3xy=3(x+y)3x-5xy+3y/-x+3xy-y=(3x+3y)-5*3(x+y)/[-x-y+3*3(x+y)]=-12(x+y)/8(x+y)=-3/2望采纳,谢谢!

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

x+y=5xy=-3(2x-3y-2xy)-(x-4y+xy)=2x-3y-2xy-x+4y-xy=x+y-3xy=5-3×(-3)=5+9=14

（x+2）^2+|y+1|=0x=-2,y=-15xy²-｛2xy²-[3xy²（4xy²-2x²y）]｝=5xy²-2xy²+3

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×(

原式=[4(x+y)-2xy]分之[(x+y)+xy]=[4(3xy)-2xy]分之[(3xy)+xy]=10xy分之2xy=5分之1

因为X+Y分之XY=2,所以XY=2(X+Y)代入后面的分子式得：13（X+Y)/5(X+Y)=13/5

（2x-3y-2xy）-（x-4y+xy）=2x-3y-2xy-x+4y-xy=（2-1)x+(-3+4)y+(-2-1)xy=x+y-3xy因为x+y=5,xy=-3所以原式=5+9=14

由A=5x*2y-3xy*2+4xy,B=7xy*2-2xy+x*2y得,A+B=6x*2y+4xy*2+2xy则,所求的式子可转化为-0.5x(6x*2y+4xy*2+2xy)-5x*2y-3xy*

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

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

x+y=3xyx^4+y^4+2(xy)^2=9(xy)^2x^4+y^4=7x^2y^2xy的负二次方+x的负二次方y=x^2/y^2+y^2/x^2=x^4+y^4/x^2y^2=7

xy/x+y=3xy=3（x+y）3x-5xy+3y/-x+3xy-y=3x-15（x+y）+3y/-x+9（x+y）-y=-12(x+y)/8（x+y）=-3/2

=xy(1-2y^2)=-0.119616

1、x²+xy=5xy+y²=-4相减x²-y²=92、相加x²+2xy+y²=(x+y)²=1x²-y²=(

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

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