已知x^2+4y^2-4x+8y+8=0,求x+y

已知x^2+4y^2-4x+8y+8=0,求x+y 已知|5x-y-8|+(7y-x+2)=0则4x+6y 已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的值 已知x^2+4y^2-2x-2x+8y+5=0,求x^2-y^2/2x^2+xy-y^2*2y-y/xy-y/(x^2+y^2/y)^2的值 已知x求^2+y^2-6x-8y+25=0求1/x-y /x+y/x^4-y^4 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 已知x-2y=2,求4x-y-8分之3x+y-6 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 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+4y-2x+8y+5=0,求x^4-y^4/2x+xy-y·2x-y/xy-y÷(x+y/y)的值.数学上交不不算请教下. 已知x^2-8x+y^2-y+16又1/4=0,求[(x+y)(x-y)-(x+y)^2-2y(x-3y)]÷4y的值 已知2x+2y=-8,4x+y=15求（x-y)^-(3x+2y)^ 已知x^2+y^2+6x-2y+10=0求8y/9x^2-y^2+4/y-3x 已知x²+y²+6x-2y+10=0,求8y分之9x²-y² + 4分之y-3x的值 已知|X-8Y|+2(4Y-1)^2+3|8Z-3X|=0求X+Y+Z 已知（x-1)2+4|y-6|=0,则5x+6y-4x+8y=?