化简求值:{(xy 2)×(xy-2)-3x² 4}÷(xy),y=-25份之1-搜答案-智慧作业帮

x^2+2xy+y^2/x^2-y^2除以x^2+xy/xy-y^2=(x＋y)²／(x＋y)(x－y)÷x(x＋y)／y(x－y)=(x＋y)／(x－y)×y(x－y)／x(x＋y)=y／

(x-2)²+∣y-3∣=0(x-2)²=0,∣y-3∣=0x=2y=3(x-y)/(x²-2xy+y²)-(xy+y²)/(x²-y

（1）4ab+8-2b2-9ab-6=-2b2-5ab+2（2）原式=3x2y-2x2y+6xy-3x2y+xy=-2x2y+7xy，当x=-1，y=-2时，原式=-2×（-1）2（-2）+7×（-1

所求之数值是1.[(xy+2)(xy-2)-(xy+2)²+8]÷(2x)={(xy+2)[(xy-2)-(xy+2)]+8}/(2x)=[(xy+2)(xy-2-xy-2)+8]/(2x)

3x²y-[2xy²-2(xy-3/2x²y)+xy]+3xy²=3x²y-2xy²+2xy-3x²y-xy+3xy²=

[(xy+2)(xy+2)-2(xy+1)+2]÷(xy)=[(xy+2)(xy+2)-2xy-2+2]÷(xy)=[(xy+2)(xy+2)-2xy]÷(xy)=[(xy)^2+4xy+4-2xy]

[（xy-2)²+4xy-4]÷(xy)=(x²y²-4xy+4+4xy-4)÷(xy)=x²y²÷xy=xy=10×1/25=2/5

xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y}=xy-2[xy-(3x²y-xy²-0.5xy)+4x²y]=xy-2(x

[2x（x2y-xy2）+xy（xy-x2）]÷x2y=[2x3y-2x2y2+x2y2-x3y]÷x2y=x-y，把x=2013，y=2012代入上式得：原式=x-y=2013-2012=1．

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

解3x²y-[2xy-2(xy-3/2x²y)+xy]+3xy²=3x²y-(2xy-2xy+3x²y+xy)+3xy²=3x²y

3xy(x²y-xy²+xy)-xy²(2x²-3xy+2x)=3x³y²-3x²y³+3x²y²-

化简结果是：-20xy+32代入得40

(1)[1/(x-1)-1/(x+1)]*(x^2-1)/x=[x+1-(x-1)]/[(x-1)(x+1)]*(x^2-1)/x=[2/(x^2-1)]*[(x^2-1)/x]=2/x根据x=√5,

[4(xy-1)^2-(xy+2)(2-xy)]除以4分之1xy=[4x^2乘以y^2-8xy+4-(4-x^2y^2)]除以4分之1xy=(4x^2乘以y^2-8xy+4-4+x^2y^2)除以4分

-6x²y(a-b)³xy²(b-a)²=-6x²y(a-b)³xy²(a-b)²=-6x^(2+1)y^(1+2)(a

化简求值(求值)

解题思路：解：x^2-3x+1=0x-3+(1/x)=0x+(1/x)=3所以x+=(x+1/x)-2=3-2=9-2=7因为网站有规定，每次只解一题，希望你在提问广场再提问一次好吗？解题过程

原式=2x2y-2xy2+3x2y2-3x2y-3x2y2+3xy2=-x2y+xy2，当x=-12，y=2时，原式=-(−12)2×2+（-12）×22=-52．

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