如果把分式x y分之xy中的x和y都扩大3bei-搜答案-神马作文网

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-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)

2（x＋3）分之x和（x－3）分之y的乘积

(3x×3y)/(3x-3y)=9xy/[3(x-y)]=3×xy/(x-y)分式的值（）(A)扩大到3倍

x+y/xy中的x,y都扩大3倍3x+3y/3x3y=3(x+y)/9xy=1/3*(x+y)/xy所以,分式的值扩大1/3倍

x分之xy算分式吗?

不算,x有可能等于0

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)

等于原来分式值的三分之一

200XY/10X+10Y=200(XY)/10(X+Y)所以分式的值扩大了10倍.

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+

y-x=3xyx-y=-3xyx-2xy-y=-5xy2x+3xy-2y=2(x+y)+3xy=-6xy+3xy=-3xy分式x-2xy-y分之2x+3xy-2y=5/3

原式为2x^2/(x+y)xy都扩大3倍后2(3x)^2/(3x+3y)=18x^2/3(x+y)=6x^2/(x+y)

（m*mxy）/（mx-my）=m（xy）/（x-y）所以（xy）/（x-y）中的xy的值都扩大m倍,那么分式的值为变成原来值的m倍了如果帮到你,请记得采纳,O(∩_∩)O谢谢

扩大3倍,4x-3y扩大三倍,x^2y^2扩大九倍,9/3=3

10x*10y/(7*10x+10y)=100xy/10(7x+y)=10xy/7x+y,不就扩大了10倍嘛

B扩大2倍.说明如下：2X2Y/(2X+2Y)=4XY/2(X+Y)=2XY/(X+Y)(不打括号的话,含义就变了,哈哈)

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