{x+2y+2=0 {7y-4y=-41 求X和Y

{x+2y+2=0 {7y-4y=-41 求X和Y x+2y+2=0 7x-4y=-41 求x和y x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x*x+2x+y*y-4y+5=0 x= y= 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 已知(3x+1)(3x-3)-3x+2)^2=-7,(y+7)(y-7)-y(y-7)=0,求8y^2-5y(-y+3x)+4y(-4y-5/2x)的值 (x-y)(x-2y)+(x-2y)(x-7y),其中X=4,Y=1.5 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 7y(x-3y)-2(3y-x)=0 .x=?,y=? (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 常微分方程的通解dy/dx=(x-y+1)/(x+y-3)y^4=2y^n+y=0y''+6y'+9y=e^(-3x)y''+y'-2y=4e^(2x) 已知|5x-y-8|+(7y-x+2)=0则4x+6y (x-4y)(2x+y)= y+y'-2y=2x 微分方程y - 2y' + y = x {2x+y/3-2y=0 2(2x+y)-5=7y 如果|x-y+1|+y^2-4y+4=0,求出x,y的值