已知X²+3XY-4Y²=0(Y≠0)求X-Y/X+Y
已知X²+3XY-4Y²=0(Y≠0)求X-Y/X+Y
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x-3y=0,y≠0,求x²-2xy+y²分之2x+y×(x-y)的值
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2x+y=0,求x-2y/x²+xy*(x²-y²)/x²-4xy+4y
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
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-3y=0,求(x²-2xy+y²/x-y)-2y的值
已知x^2+3xy-4y^2=0(y≠0),求x-y/x+y的值.
已知x/2=y/3(xy≠0),求x²-2xy-3y²/x²-6xy-7y²的值
已知x,y>0 2x+y+3=xy 求5x+4y最小值