已知x,y∈R,满足x²+y²-4x-6y+12=0 1.y/x的范围,2.x²+y
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
已知非零有理数x,y满足x²-4xy+4y²=0,求x-y/x+y-y-x/x+y的值.
已知实数x,y满足x²+4y²=4x,求x+y的取值范围
已知集合A={(x,y)|x²+y²≤1.x.y∈R},B={(x,y)||x|+|y|≤2.x.y
已知实数x、y满足x²+y²+4x-6y+13=0
已知实数x,y满足x²+y²=1.求x²-4x+y²+2y的取值范围,求详解,
已知实数X,Y满足X²+Y²+4X+3=0,求Y-2/X-1的取值范围.
已知实数x,y满足{x≧0 y≧x 4x+3y≦12}.z=2y+3/x+1 的取值范围
若实数X,Y满足X²+Y²+4X-2Y +1=0,则X²-6X+Y²-2Y的最大
已知实数x,y满足x²+y²-6x-4y+12=0,求x-y的最大值与最小值
已知实数x, y满足x²+y²-2x+6y+10=0,求y∧-x.
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y