4x²y-5x³-y² 7xy³-6 7

题目写错应该是求（6xy+7y)+[8x-(5xy-y+6x)]（6xy+7y)+[8x-(5xy-y+6x)]=6xy+7y+8x-5xy+y-6x=xy+2x+8y=xy+2(x+4y)=5+2×

解题思路：提取公因式进行分解解题过程：附件最终答案：略

-x^y^7+y^8)(这里有问题,x的几次方?再问：就是一次方再答：(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-xy^7+y^8)(x^2+xy+y^2)=（x^8-x^7y+x^

5x²-3xy-4y²-11xy-7x²+2y²=-2x²-2y²-14xy=-2(x²+y²)-14xy=-2×7-1

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

解题思路：本题是求整式的值，注意一定要先化简，再求值。化简就是先去括号，在合并同类项。解题过程：解：（6xy+7y）+[8x-（5xy-y+6x）]=（6xy+7y）+[8x-5xy+y-6x]=6x

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

(x*x+y*y)(x*x+y*y)-4x*x*y*y=(x^4-2x^2y^2+y^4)=(x^2-y^2)^2=0x^2=y^2x/y=±1(x*x+5xy+y*y)/(x*x+2xy+y*y)=

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,

(x-y)^8

（4xy+12y)+[7x-(3xy+4y-x)]=4xy+12y+7x-3xy-4y+x=xy+8x+8y=xy+8(x+y)=(-2)+8*3=-2+24=22

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

原式=-2x^2-2y^2-3xy-11xy=-2*7-14*(-1)=0

（7xy+4x-7y）+(6x-3xy)-(3y+4xy)=7xy+4x-7y+6x-3xy-3y-4xy=10x-10y=10（x-y）=10*3=30

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

5x^2-(3xy+4y^2)-(11xy-2y^2)-7x^2=5x^2-3xy-4y^2-11xy+2y^2-7x^2=-2x^2-2y^2-14xy=-2(x^2+y^2)-14*xy=-2*7

x^5+y^5-(x^4y+xy^4)=(x^5－x⁴y)－(xy⁴－y^5)=x⁴(x－y)－y⁴(x－y)=(x⁴－y⁴)(

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-

[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-x)^29^-x*27^y=3^-2x*3^3y=3^(-2x+3y)=3^(-

原式={[(x-y)^2+4xy]/(x-y)}{[(x+y)^2-4xy]/x+y}={[x^2-2xy+y^2+4xy]/(x-y)}{[x^2+2xy+y^2-4xy]/x+y}={[x^2+2