[-3xy] 2y*2y 3x-搜答案-搜搜考试网

[23x−2x+y(x+y3x−x−y)]÷x−yx=[23x−2x+y•x+y3x+2x+y•(x+y)]•xx−y=(23x−23x+2)•xx−y=2xx−y故答案为2xx−y．

3y^2=12y3y^2-12y=03y(y-4)=0y1=0,y2=43x^2-5x=0x(3x-5)=0x1=0,x2=5/3（x+3)^2=2x(x+3)x^2+6x+9=2x^2+6xx^2=

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)

x^2-xy-6y^2+3xy+y+2

3xy是3x原式=(x-3y)(x+2y)+3x+y+2十字相乘x-3y2×x+2y1所以原式=(x-3y+2)(x+2y+1)

1.2(Xy+Xy)-3(Xy-xy)-4Xy=2*2xy-0-4xy=4xy-4xy=02.1/2ab-5aC-(3acb)+(3aC-4aC)=1/2ab-5ac-3acb-ac=1/2ab-6a

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

3xy[2xy-x(y-2)+x-1]=3xy(2xy-xy+2x+x-1)=3xy(xy+3x-1)=3x^2y^2+9x^2y-3xy

3xy[2xy-x（y-2）+x]＝3xy[2xy-xy+2x+x]=3xy(xy+3x)=3x²y²+9x²y

(-3x^y+2xy)-(4x^+xy)=-3x^y+2xy-4x^-xy=-3x^y+xy-4x^所以填上-3x^y+xy-4x^

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

5x^2y/-1/2xy*3xy^2=-7.5x²y²

解方程组2x−5＝y，①3x−2y＝12，②时，把①代入②即可消去y，达到消元的目的；解方程组2x+3y＝133x−4y＝−6时，想法把y的系数化为相同，然后用减法化去，达到消元的目的．故答案是：代入

x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2=16x^3y^3-49x^3y^3-45^3y^3=-78x^3y^3如果本题有什么不明白可以追问,

y的平方+4=6Y公式B平方-4乘A乘CA=1B=-6C=4《A为2次项系数.》即：36-16=20Y=《-B+-根号B平方-4乘A乘C》除以2A最后Y=3+2倍根号5和3—2倍根号5

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

1.15-9y-9x＞-9/43.3(x-1)-x+1212x>32X＞8/3

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

[23x-2x+y（x+y3x-x-y）]÷x−yx=（23x-23x+2）×xx−y=2xx−y，∵5x+3y=0，∴y=-53x，∴原式=2xx+53x=34．

y^3+xy^2+2xy+x^2-1=(x+y-1)(x+y^2+y+1)再问：烦写出过程再答：

原式=-x²y+2xy²+2x²y²-4xy³-3x³+27x³y-18x²y²+2x²y-18x&

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