已知x.y为正整数,且满足2x2+3y2=4x2y2+1,求x2+y2的值
2010.09.已知x、y为实数,且(x2+y2)(x2+y2+1)=20,求x2+y2的值
已知x,y为实数,且(x2 +y2)(x2 +y2+2)=3.求x2 +y2的值
已知实数x.y满足(x2+y2)(x2+y2-1)=2,求x2+y2的值
已知x2+4y2+x2y2-6xy+1=0,求 x4-y4/2x-y 乘 2xy-y2/xy-y2 除以(x2+y2/x
已知x,y都是正整数,且满足4x2-9y2=31.求x、y的值.
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知实数x,y满足x2+y2=2x,则x2y2的取值范围是______.
已知xy/x+y=1/3,x2y2/x2+y2=1/5,求xy的值.
已知x+y=4,x2+y2=14,求x3y-2x2y2+xy3的值.
已知x2+y2-4x-10y+29=0求x2y2+2x3y2+x4y2的值
已知非零实数x,y满足:x2+xy-2y2=0,求(x2+3y+y2)/(x2+y2)的值
正整数x,y满足x2-y2=2xy,求x-y/x+y的值