若正整数x,y满足x2+y2=1997,则x+y等于 ______.
若实数x,y满足3x2+2y2=6x,则x2+y2的最大值为______.
已知正整数x,y满足2x+49=y2,则x=______,y=______.
正整数x,y满足x2-y2=2xy,求x-y/x+y的值
若实数x,y满足x2+y2-2x+4y=0,则x-2y的最大值为______.
若实数x、y满足约束条件|x|+|y|≤1,则z=x2+y2-2x-2y的最大值为______.
若实数x、y满足x2+y2-2x+4y=0,则x-3y的最大值是______.
若实数x,y满足x2+4y2=4x,则S=x2+y2的取值范围是______.
已知实数x,y满足x+y=1,则x2+y2的最小值是______.
已知实数x,y满足2x-y-5=0,则x2+y2的最小值为______.
实数x、y满足x2+y2=4,则x+y-xy的最大值为______.
若正整数x,y满足x2-y2=64,则这样的正整数对(x,y)的个数是( )
已知实数x、y满足(x2+y2)(x2+y2-1)=2,则x2+y2的值为______.