已知(x²+y²)²-(x²+y²)-12=0,则x²+y&
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
已知:x²y²-2x+6y+10=0则x+y=
已知x²+4x+y²-2y+5=0,则x+y=
已知y+y'*x²=0,求y=?
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
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+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
已知x+y=4,x²-y²=20,则x-y=?
已知x²-y²=12,x+y=6,求x,y的值
已知实数x、y满足x²+y²+4x-6y+13=0
已知x²+y²-2x+4y+5=0,求x+y