作业帮3x 4y 2=0x^2 y^2-2x=0
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/27 23:18:00
(2x+y)/(x^2-2xy+y^2)X(x-y)=(2x+y)/（x-y）²*（x-y)=(2x+y)/（x-y）x-3y=0,x=3y(2x+y)/（x-y）=（6y+y）/（3y-y
3x=4Y.X/Y=4/3,x-y)/y=(X/Y)-1=1/3,（3x+2y)/(2x+3y)=(4Y+2y)/(8/3y+3y)=18/17（因为3x=4Y,2x=8/3y）再问：若3X-4Y=0
2x-y-3=3x+2y+1=0,x=5/7,y=-11/7
X+Y分之X-Y等于3x=-2yX+Y分之2(x-y)减X+Y分之3X+Y=(-x-3y)/(x+y)=1
因为(x-y)/(x+y)=3,则(x＋y)/(x－y)＝1/3则5(x-y)(x+y)-(x+y)/2(x-y)＝5*3-1/(3*2)=15-1/6=89/6
c∵x+y≠0∴x≠-y∵3x-6y/x+y=0∴3x-6y=0∴x=2y∴x=2y且x≠-y
x=-1,y=1xy=-1(2xy)2(x2-y2)-(-3xy)3+9x2y4-9x4y2＝4(xy)2(x2-y2)-(-3xy)3－9（xy)2（x2-y2）＝-5(xy)2(x2-y2)+27
3x^2+xy-2y^2=0推出(3x-2y)(x+y)=0推出x=-y或x=(2/3)y{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}/x^2-9y^2推出：{
3x^2y+x^3y'+3y^2y'-2=0=>(x^3+3y^2)y'=2-3x^2y∴y'=(2-3x^2y)/(x^3+3y^2)
3x-5y=0,则x+y/x=（8/5）,x-y/y=（2/3）,2x-3y/2x+3y=(1/19)因为3x-5y=0所以3x=5y设x=5,y=3,可以解得3x-5y=0,则x+y/x=（8/5）
线性规则,画出可行性区域,得出x=4/5,y=12/5时,z的最大值为48/25
2x+y/x^2-2xy+y^2)*(x-y)=2x+y/(x-y)^2*(x-y)=2x+y/x-yx-3y=0.x=3y将x=3y带入2x+y/x-y=6y+y/3y-y=7/2（二分之七）
由x²+y²-4x-10y+29=0得（x-2）²+（y-5）²=0所以x=2y=5所以x²y²+2x^3*y²+x^4*y&su
（1）A=3+3x-2x-2x2+3x+4x2-1=2x2+4x+2；（2）方程变形得：x2+2x=5，则A=2（x2+2x）+2=12．
x=-2.5y=-3再问：过程再答：2x+y/3-2y=0①2(2x+y)-5=7y②展开②式，4x+2y-5=7y，移项整理的得4x-5y=5③将①整理得2x-5y/3=0④将④×2得4x-10y/
解(x-y)(x+y)-(x-2y)²+x(3x-5y)-(x-y)(x-2y)=(x²-y²)-(x²-4xy+4y²)+(3x²-5xy
x=3y代入(2x+y)/(x^2-2xy+y^2)*(x-y)=7y/(9y^2-6y^2+y^2)*(2y)=7/2
x-3y=0x=3y原式=(2x+y)(x-y)/(x²-2xy+y²)=(2×3y+y)(3y-y)/[(3y)²-2×3y×y+y²]=7y×2y/(9y&
∵x^2-3y^2=2xy∴x^2-2xy-3y^2=0∴（x+y）（x-3y）=0∵x>0,y>0∴x-3y=0∴x=3y∴x+2y/x-y=3y+2y/3y-y=2y+2/3或=2/3(x+1)如