y=2x^2,y=2（x-4）^2和y=2（x+1）^2在同一坐标系中画出他们的图像分别说去各个函数图像的看口方向对称轴和顶点坐标

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 y'=（y/x）^2+y/x+4微分方程 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x-4y)(2x+y)= y+y'-2y=2x {x+2y+2=0 {7y-4y=-41 求X和Y 微分方程y - 2y' + y = x 4x方y/(x-2y)(x+2y)怎么算[x方/x-2y]-4x方y/(x-2y)(x+2y)=? 3x+y=2 -y/x+y=123x+y=2 （-y/x）+y=12 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 求y''+2y'+y=e^-x/x的通解y''+2y'+y=（e^-x）/x (x+y)^2(x-y)^2(x^4+x^2y^2+y^4)=? 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 x*x+2x+y*y-4y+5=0 x= y= 如果|X|=4 |Y|=2 且|X+Y|=X+Y 求X+Y {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1