作业帮x 2y x-2y分之4y^2 4y^2-x^2分之4x^2y
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/22 05:10:45
2x-y分之x+y=2,则2x-y=2(x+y)4x-2y分之x+y-4x+4y分之2x-y=2(2x-y)分之x+y-4(x+y)分之2x-y=4(x+y)分之x+y-4(x+y)分之2(x+y)=
x+y分之4x-2y-2x-y分之4x+4y=2(2x-y)/(x+y)-4(x+y)/(2x-y)=2*2-4*(1/2)=4-2=2
33/56
3）把①式乘以10,②式乘以6,得：25x+2y=-402x+y=1由下式得y=1-2x,代入上式得25x+2-4x=-4021x=-42x=-2则y=1+4=54）把①式乘以6,②式乘以2得3x-y
因为x+y分之2x-y=2又因为x+y分之4x-2y是它的2倍所以x+y分之4x-2y就=4因为x+y分之2x-y=2倒过来2x-y分之x+y就为1/2又2x-y分之4x+4y是2x-y分之x+y的4
3y-（3y+5）/6=(1+2y)/2-(5y-4)/4,两边都乘以12,得36y-2(3y+5)=6(1+2y)-3(5y-4),36y-6y-10=6+12y-15y+12,33y=28,y=2
x^2+y^2-4x-2y+5=0,即(x-2)^2+(y-1)^2=0所以x=2,y=1所以√(x+y)/√(8y-2x)=√3/2望采纳
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
-2y+y4=5-1/3合并得-7y/4=14/3两边同乘12得-21y=42化简得y=-2
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
y+1/y=7两边平方得y²+2+1/y²=49∴y²+1/y²=47两边再平方得y的4次方+2+1/y的4次方=47²y的4次方+1/y的4次方=2
6y-(y+2分之y+2-y分之y)除以y³-4y-2y²+8分之y=6y-[(2y-y²+2y+y²)/(4-y²)]÷y/(y-2)³=
(x+y)/2+(x-y)/2=7====>x=74(x+y)-5(x-y)=2====>-x+9y=2将x=7代入-x+9y=2====>y=1所以x=7,y=1.
=3x/(x-4y)-(x+y)/(x-4y)-7y/(x-4y)=(3x-x-y-7y)/(x-4y)=(2x-8y)/(x-4y)=2(x-4y)/(x-4y)=2
解题思路：这是分式的除法，先变乘然后把分子分母因式分解，最后进行约分化成最简分式。解题过程：
X=3Y+4/5Y-2则X（5Y-2）=3Y+45XY-2X=3Y+4(5X-3)Y=2X+4则Y=2X+4/5X-3
x-4y分之3x+4y-x分之x+y-x-4y分之7y=3x/(x-4y)-(x+y)/(x-4y)-7y/(x-4y)=(3x-x-y-7y)/(x-4y)=(2x-8y)/(x-4y)=2
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
3y-6分之3y+5=2y-4分之5y-4方程两边同时乘以6(y-2),得2(3y+5)=3(5y-4)则6y+10=15y-12,解得y=22/9检验：将y=22/9代入原方程,左边=右边所以y=2