已知(x²+y²)(x²+y²-8)+16=0 求x²+y²
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知X²+3XY-4Y²=0(Y≠0)求X-Y/X+Y
已知y+y'*x²=0,求y=?
已知x²+4y²-6x+8y+13=0,求x-y/x+y的值.
x²+y²-6x+8y+25=0求(x-y)-²
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知(x-3)²+|x+y|=0,求:
已知非零有理数x,y满足x²-4xy+4y²=0,求x-y/x+y-y-x/x+y的值.
已知x-3y=0,y≠0,求x²-2xy+y²分之2x+y×(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.
已知2x-y=10,求代数式[(x²+y²)-(x-y)²+2y(x-y)]÷4y的值?