[ 2x y]的平方-2[2x y][x-2y] [-搜答案-搜搜考试网

解2(x²-xy)-3(2x²-3xy)=(2x²-6x²)+(-2xy+9xy)=-4x²+7xy再问：��|-15|-8�£�-2��+4*�

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

-2x平方-12xy平方+8xy立方=-2x(x+6y平方-4y立方)（2a+3分之1b）（3分之1b-2分之1a）=9分之1b²-a²+2分之1a

2xy/(y的平方/x)

2xy/(y^2/x)=2xy÷(y^2/x)=2xy×(x/y^2)=2x^2/y再问：O(∩_∩)O谢谢

(x+1)^2+|y-1|=0(x+1)^2>=0|y-1|>=0x+1=0,y-1=0x=-1,y=12(xy-5xy的平方)-(3xy的平方-xy)=2xy-10xy^2-3xy^2+xy=3xy

条件是(x+1)^2+|y-1|=0,是吗?如果是它的话,那么x=-1,y=1.带入原式,得值为2

2x²-3xy+(2xy-x²)=2x²-3xy+2xy-x²=x²-xy=x(x-y)

x的平方-2xy/xy-2y的平方＝x(x-2y)/y(x-2y)=x/y

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原式(-xy/3)²*[xy(2x-y)-2x(xy-y²)]=(x²y²/9)(2x²y-xy²-2x²y+2xy²)

M-(2x^2-3xy+xy^2)(-xy)=(2x^2y+xy^2)(x-2y)M=(2x^2y+xy^2)(x-2y)-(xy)(2x^2-3xy+xy^2)=2x^3y-4x^2y^2+x^2y

a-2b=(5x²y-3xy²+4xy)-2(7xy²-2xy+x²y)=5x²y-3xy²+4xy-14xy²+4xy-2x&#

3x²y-{2xy-2(xy-3/2x²y)}+xy=3x²y-{2xy-2xy+3/2x²y}+xy=3x²y-2xy+2xy-3/2x²

2xy×(-x的平方y)

解2xy×(-x²y)=-2x³y²a³b²/3×(-3ab²/2)²——这个吗=a³b²/3×(9a

原式=-x^2+2xy-y^2-2xy+6x^2+6y^2-3xy=5x^2-3xy+5y^2

解x²+2y²-2xy+4y+4=0吧(x²-2xy+y²)+(y²+4y+4)=0(x-y)²+(y+2)²=0∴x-y=0,y

(x+y)^2>=0,(y-1)^2>=0,因此y=1,x=-1.原式=2(-1-5)-(-3+1)=-10再问：打错了是已知(x+1)的平方+(y-1)的绝对值=0,求2(xy-5xy的平方）-（3

4种x=-3,y=4x=-1,y=4x=1,y=-4x=3,y=-4

原式=-x³y^6+x²y^4+xy²=-(xy²)³+(xy²)²+(xy²)=-2³+2²+2=

2x平方y-2xy+3xy平方+5+2xy+x平方y-3xy平方-3=2x²y-2xy+3xy²+5+2xy+x²y-3xy²-3=3x²y+2