若x² +xy+y² =14,x² -xy+y²=28求x+y的值

若x² +xy+y² =14,x² -xy+y²=28求x+y的值 若x²+xy+y²=14,x²-xy+y²=28,求x+y的值 已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值 若x²+xy+y=14,y²+xy+y=28,求x+y的值 已知x²y²+x²+y²=10xy-16 求x,y 已知X²-5XY+6Y²=0,求(X²+3XY)\2Y²的值 x²+y²+4x-8y+20=0,求分式x²-y²/xy的值 1.若x+y=3,xy=1,求(x-y)²,x²+y²的值. 已知x/y=3,求x²+2xy-3y²/x²-xy+y³的值 .已知xy=8满足x²y-xy²-x+y=56,求x²+y²的值 2.若x-3= 若x/y=2,求7x²-3xy+2y²/2x²-3xy+7y²的值 答案是8/3 若x/y=2,求分式(x²-xy+3y²)/(x²+xy+6y²)的值