(2分之x-y)的平方-4分之1乘(x y)(x-y)

①-x+2y分之x-y除以x的平方+4xy+4y的平方分之x的平方-y的平方=-(x-y)/(x+2y)÷(x^2-y^2)/(x^2+4xy+4y^2)=-(x-y)/(x+2y)×(x^2+4xy

1-（x-y）/(x+2y)÷(x²-y²)/(x+2y)²=1-(x-y)/(x+2y)×(x+2y)²/(x+y)(x-y)=1-(x+2y)/(x+y)=

3x^2+xy-2y^2=(3x-2y)(x+y)=0x=-2y/3,或x=-y但由于你要求的式子中分母里有X平方-Y平方x=-y舍去其他就代入吧

原式=2xy/(x+y)(x-y)+x(x-y)/(x+y)(x-y)=(2xy+x²-xy)/(x+y)(x-y)=(x²+xy)/(x+y)(x-y)=x(x+y)/(x+y)

您好：原式=2x/(2x+3y)(2x-3y)-1/(2x+3y)=(2x-2x+3y)/(2x+3y)(2x-3y)=3y/(2x+3y)(2x-3y)如果本题有什么不明白可以追问,如果满意记得采纳

朋友想念你很高兴为您解答!请放心使用,有问题的话请追问采纳后你将获得5财富值.你的采纳将是我继续努力帮助他人的最强动力!再问：答案应该是8y的四次方分之3x的平方y的三次方+x的三次方吧再答：根据题意

设x/2=y/3=z/4=a则:x=2a;y=3a;z=4a代入得：(xy+yz+zx)/(x^2+y^2+z^2)=(6a^2+12a^2+8a^2)/(4a^2+9a^2+16a^2)=26a^2

（x的平方-y的平方)分之2xy+(x+y)分之x-(y-x)分之y=（x的平方-y的平方)分之2xy+(x+y)分之x+(x-y)分之y=(x²-y²)分之[2xy+x(x-y)

前者分子：x^2-y^2=(x+y)(x-y)那前面这项就可以化简约分啦后者分子：4x^2-4xy+y^2=(2x)^2-2*2xy+y^2=(2x-y)^2建议你理解一下x^2-2xy+y^=(x-

=-(x+2y)(x-2y)/(x+y)²×2x(x+y)/(x-2y)=-2x(x+2y)/(x+y)=-(2x²+4xy)/(x+y)

（x分之x-y）-（y分之x+y）+（2xy分之x的平方-y的平方）=1-y/x-1-x/y+(x^2-y^2)/2xy=-2(y^2+x^2)/2xy+(x^2-y^2)/2xy=-(x^2+3y^

x的平方+2xy+y的平方分之x的平方-4y的评方÷x的平方+xy分之x+2y=(x+2y)(x-2y)/(x+y)²×x(x+y)/(x+2y)=x(x-2y)/(x+y)=(x²

x平方+y平方+2xy分之x平方-4y平方除以x平方+xy分之2y+x=(x-2y)(x+2y)/(x+y)²·x(x+y)/(x+2y)=x(x-2y)/(x+y)

设x/2=y/3=z/4=k∴x=2k,y=3k,z=4k∴（xy+yz+zx）/（x²+y²+z²）=（6k²+12k²+8k²）/（4k

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

x+2y+4y^2/(x-2y)-4x^2y/(x-4y^2)=x+2y+4y^2/(x-2y)-4x^2y/[(x+2y)(x-2y)]通分,分母为[(x+2y)(x-2y)]=(x+2y)(x+2

(x^2-4y^)\(x+y)^2乘以2x(x+y)/(x+2y)=2x(x-2y)\(x+y)

解(-3/4x²y-3/5xy²)(-2/3xy)²=(-3/4x²y-3/5xy²)(4/9x²y²)=-1/3x^4y

x的平方-64y的平方分之2x-x-8y分之1=[2x-(x+8y)]/(x-8y)(x+8y)=(x-8y)/(x-8y)(x+8y)=1/(x+8y)

x-y分之2x的平方-y-x分之x的平方-4xy+x-y分之2y的平方-x的平方=2x/(x-y)-(x²-4xy)/(y-x)+(2y-x²)/(x-y)=(2x+x²