若x^2-4x+y^2+2y+5=0,求x,y的值

已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 x平方+y平方-2x-4y+5=0求x,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* 若x^5+x^4y+x^4+x+y+1=0,且3x+2y=1,求x,y的值 若|x+y-1|+（x-y-2)²=0,求代数式（x+2y)(x-2y）-（2x-y)(-y-2x)的值. 若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值 若2x-y=0,求代数式[(x^2+y^2)-(x-y)^2+2y×(x-y)]÷4y的值 已知5x-4y=0且xy不等于0,求x^2+y^2/x^2-y^2-x+y/x-y的值 设x,y是有理数,并且x,y满足x^2+2x+y^2-4y+5=0求x+y的值 已知x^3+xy^2+x+x^2y+y^3+y=0,求5x-6y/3x+4y的值. 已知x+4y-2x+8y+5=0,求x^4-y^4/2x+xy-y·2x-y/xy-y÷(x+y/y)的值.