x²-9xy-52y²

计算：(xy-x²)×x-y/xy x²/xy-x/y [-xy/(x-y)²]²×(y²-xy/x)³ x/xy-y²与y/x²-xy 通分 x-y/x²÷x²-2xy+y²/xy*（xy-x²） 计算：x²+2xy+y²/xy-y².x²-2xy+y²/xy+y&# 计算：（xy-x²）乘 x-y分之xy 已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
X²+2xy+y²/xy乘x²-2xy+y²/xy+y²= 分式（x²-y²\xy）-（xy-y²\xy-x²）可化简为 (xy分之x²-y²)-(xy-x²分之xy-y²) 2x²+6x+y²=2xy-9,求xy平方