若x-2y=2,求x^2-4y^2-8y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 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 如果|X|=4 |Y|=2 且|X+Y|=X+Y 求X+Y 若x*x+y*y=x+y-1/2,求x,y的值如题 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 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-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 若实数x、y满足x平方+y平方-4x-2y+5=0,求根号8y-2x分之（根号x）+y 若实数X,Y满足x²+y²-4x-2y+5=0求√x+y/√8y-2x 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 若x-2y=2,求x^2-4y^2-8y的值. 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) RT,若（√2x-y）+y^2+4y+4=0,求[(x-y)^2+(x+y)(x-y)]÷2x的值 已知x+y/y=11/8,求x-y/x+2y的值.