已知xy=1/9,0
已知xy>0,证明xy+xy/1+x/y+y/x>=4
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
已知实数xy满足x²﹢y²-xy+2x-y+1=0求xy
已知实数x、y满足xy>0,且8/xy+1/x+1/y=1,
已知x-y=xy(xy不等于0),请你求出1/x-1/y的值
已知x-y=xy(xy不等于0),请你求出1/x-1/y的值,
已知|x+y+1|+|xy+3|=0,求代数式xy^3+X^3y
已知:xy+x=-1,xy-y=-2.
已知x-y=3xy,且xy不等于0,则-3x+6xy+3y/(7x-5y)-9xy-(3x-y)
已知(x+1)的平方=/Y-1/=0,求2(xy-xy的平方)-(3xy-xy)的值.
已知x,y是实数,且适合方程(xx+xy-12)(xx+xy-12)+(xy-2yy-1)(xy-2yy-1)=0求x,