若分式x y分之x的平方中的x和y都扩大10倍-搜答案-搜搜考试网

2/xy=2(y-x)/xy(y-x)3y/(xy-x^2)=3y^2/xy(y-x)如果不懂,请追问,祝学习愉快!

x-3y=0且xy≠0,所以x=3y(x≠0,y≠0)带入分式,(9y-3y+y)/(9y+3y+y)=7/13

x-y=x/y两边同乘以y得xy-y^2=x移项xy-x=y^2即x(y-1)=y^2x=y^2/(y-1)

x/y=3=>x=3y原式=(9y²+2*3y*y-3y²)/(9y²-3y*y+y²)=12/7再问：能不能先化简，后代入？再答：可以是可以，x²+

x平方减y平方等于0,(x+y)(x-y)=0x+y=0或x-y=0当x+y=0,则x=-y3x平方减2xy加4y分之x平方减3xy加5y平方=(3y²+2y²+4y²)

(4-x²)/(x²y-2xy)=-(x²-4)/(x²y-2xy)=-(x+2)(x-2)/xy(x-2)=-(x+2)/xy愿对你有所帮助!

∵x/y=2/3∴设x=2t,y=3t∴(x²+3xy)/(x²+xy-6y²)=(4t²+3×2t×3t)/(4t²+2t×3t-6×9t²

xy+x/x的平方+2x+1=x(y+1)/(x+1)^2不能继续约分了题目如果是xy+y/x的平方+2x+1=y(x+1)/(x+1)^2=y/(x+1)

原式=x(x+y)分之x(x-y)=(x+y)分之(x-y)

xy/(x+y)变为3Xx3Y/(3X+3Y)=3XY/(X+Y)

正确答案是C.若是3x+4y=0的话,那分式出的就没意义了,考虑问题不要太偏激!那要是你所说,所有的分式分子都为0的话,还不用计算了呢!所以说你那是特殊情况,比如说,我说四边形的四个角是直角,你判断他

(x+3y)/(x²+xy)+(y-x)/(xy+y²)=(x+3y)[x(x+y)]-(x-y)/[y(x+y)]=[(x+3y)y-x(x-y)]/[xy(x+y)]=(xy+

因为x=3y,所以原式=[（3y)²-3y·y+y²]分之[(3y)²+2·3y·y-3y²]=7y²分之12y²=7分之12

x²-3xy+2y²=(x-y)(x-2y)=0x-y≠0,所以x-2y=0x=2y原式=(4y-3y)/(2y-y)=y/y=1

分式(x+y)的三次方分之11/(x+y)^3x的平方+2xy+y的平方分之11/(x^2+2xy+y^2)=1/(x+y)^2x-y分之11/(x-y)最简公分母是(x+y)^3*(x-y)=(x-

xy/(x²-y²)=xy/(x+y)(x-y)=x*(-2x)/(x-2x)(x+2x)=-2x²/(-3x²)=2/3

方法一：取特殊值x=1,y=2,代入即可.方法二：由y/x=2,得y=2x,代入要求的式子也行,但是注意运算要小心点.

(2x^2+3xy-2y^2)/(x^2+3xy+2y^2)={(2x-y)(x+2y)}/{(x+y)(x+2y)}=(2x-y)/(x+y)=02x-y=0

(x+y)分之(x的平方-xy+y)是最简分式;

x/y=2则x=2y代入下式(x^2+y^2)/xy=（4y^2+y^2）/(2y^2)=5/2