1-x-y^2分之1 x不改变式子的值-搜答案-智慧作业帮

原式=[(x+2y)/(x+y)][xy/(x+2y)]÷[(x+y)/xy]=[xy/(x+y)]×xy/(x+y)=x²y²/(x+y)²

[(2/3x)+y]/[2x-(5/2y)]分子分母同乘以3x.=(2+3xy)/[6x^2-(15x/2y)]再分子分母同乘以2y.=(4y+6xy^2)/(12x^2y-15x)等于(12x^2y

1 x^2y分之x^4

1x^2y分之x^4=x²/y2ab分之ab-b^2(b不等于0）=1-b/a36abc^2分之36ab^3c=6b²/c4a^2-b^2分之（a+b)^3=（a+b）²

只要把负号移到分数前去

0.5=二分之一4分之12分之10.2=五分之一2,4,5的最小公倍数为20分子分母同*20得(10-5X)分之(10X-4y)

(0.5x-1/3y)/(0.25x-0.2y)（分子分母同时乘以60）=(30x-20y)/（15x-12y）

（2x+(y-1)）(2x-(y-1))=4x^2-(y-1)^2(3x+y)(3x-y)=9x^2-y^2相减得4x^2-y^2+2y-1-9x^2+y^2=-5x^2+2y-1带入得-5*1/25

第一个两边乘128(x-y)-3(x+y)=-128x-8y-3x-3y=-125x-11y=-12(1)第二个6x+6y-8x+4y=16-2x+10y=16x-5y=-8(2)(1)-(2)×55

怎么会又-2x又-x,题目打得对么.

原式=1/2x-1/(x+y)[(x+y)/2x-(x+y)]=1/2x-(1/2x-1)=1/2x-1/2x+1=1

1、(xy分之x²-y²)×(x-y分之x)-(y分之x)；=(x+y)(x-y)/xy×x/(x-y)-x/y=(x+y)/y-x/y=(x+y-x)/y=12、6xy²

原式=[(x+2y)/(x+y)]×[xy/(x+2y)]÷[(x+y)/xy]=[(x+2y)/(x+y)]×[xy/(x+2y)]×[xy/(x+y)]=x²y²(x+2y)/

2x/(x²－64y²)-1/(x-8y)根据公式：a²-b²=(a+b)(a-b)=2x/(x+8y)(x-8y)-1/(x-8y)通分=2x/(x+8y)(

-3x+1分之2-x=3x-1分之x-2

整理方程①3﹙x＋y﹚＝36－2﹙x－y﹚3x＋3y＝36－2x＋2y3x＋3y＋2x－2y＝365x＋y＝36③整理方程②4x＋4y－5x＋5y＝2－x＋9y＝2x＝9y－2④④代入③,得5﹙9y－

是这样的形式吗?[x/（x+y）+2y/（x+y）]×[xy/（x+y）]÷（1/x+1/y）一:原式=（x+2y）/（x+y）×[xy/（x+2y）]÷[（x+y）/xy]=x²y&sup

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)

设1/(x-y)=a,1/(x+y)=b则原方程组变成：2a+b=1/4b-a=1解得：a=-1/4,b=3/4则1/(x-y)=-1/41/(x+y)=3/4解得：x=-4/3,y=8/3

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