x,y满足x2+2xy+3y2=2,x+2y的范围
设实数xy满足x2 +2y2=6,则x+y的取值范围
正整数x,y满足x2-y2=2xy,求x-y/x+y的值
整数x,y满足x2-y2=2xy,求x-y/x+y的值
正数xy满足x2-y2=2xy,求x+y分之x-y的值
已知实数x,y满足x2+2xy+3y2-8y+6=0,求x,y的取值范围
已知x、y是实数且满足x2+xy+y2-2=0,设M=x2-xy+y2,则M的取值范围是______.
实数x、y满足x2+xy+y2=2,记u=x2-xy+y2,则u的取值范围是
已知实数x、y满足2x2-7xy+3y2=0,求x:y
已知非零实数x,y满足:x2+xy-2y2=0,求(x2+3y+y2)/(x2+y2)的值
已知实数XY 满足X2+Y2=1,求Y+2/X+1的取值范围
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知实数x,y满足(x2)+(y2)-xy+2x-y+1=0,求x,y的值