已知x²-xy-2y²=0,(x≠0,y≠0)求(x²-2xy)/(xy+y²)
已知x/2=y/3(xy≠0),求x²-2xy-3y²/x²-6xy-7y²的值
x+2y=0(x≠0),求分式x²-xy分之2xy+y²
已知x+2y=0,xy≠0,求x²-2xy/xy+y²的值(/是分数线)
已知2x+y=0,求x-2y/x²+xy*(x²-y²)/x²-4xy+4y
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知2x²-xy-2y²=0,(xy不等于0)求x分之y
已知X²+3XY-4Y²=0(Y≠0)求X-Y/X+Y
已知x-3y=0,y≠0,求x²-2xy+y²分之2x+y×(x-y)的值
已知(x+3)+丨X-y+10丨=0 ,求5x²y-[2x²y-(3xy-xy²)-3x&
已知x²-7xy+12y²=0求x²-xy+y²/2xy的值
已知实数xy满足x²﹢y²-xy+2x-y+1=0求xy
已知2x²+3xy-2²=0(xy≠0),求x-y分之x+y的值