圆A:x^2+y^2+4x+2y+1=0与圆B:x^2+y^2-2x-6y+1=0的位置关系是A相切B相离C相交D内含

已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 A={(x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0A={(x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0 已知集合A={(x,y)|2x-y+2>=0,x-2y+1 方程组{ X+Y=1 X-Y=2a }的解满足 {x>0 y 集合A={（x,y)|y=-x^2+mx-1},B={(x,y)|y=3-x,0 如果A={（x,y）|x,y+2>0},B={（x,y）|2x+3y-6>0},C={（x,y）|x-4 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x*x+2x+y*y-4y+5=0 x= y= {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 {4x-3y-10=0 3x-2y=0,{3x-4(x-y)=2 2x-3y=1,{2(x+y)-(x-y)=3 (x+y)-2(x-y)=1 已知x属于R,y>0,集合A={x|x*x+x+1,-x,-x-1},集合B={-y,-y/2,y+1}若A=B,则x*x+y*y的值为 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 圆x²+y²-x+2y=0关于直线x-y+1=0对称的圆的方程是A、x²+y²+4x-3y+5=0B、x²+y²+4x+3y+5=0C、x²+y²-4x-3y+5=0D、x²+y²+4x+3y-5=0 (2x+y)(2x-3y)+x(2y+y) 2a(x-y)-4b(x-y) 设平面点集A={(x,y)|(y-x)(y-1/x)>=0},B={(x,y)|(x-1)^2+(y-1)^2 设平面点集A={(x,y)|(y-x)(y-1/x)>=0},B={(x,y)|(x-1)^2+(y-1)^2 设平面点集A={(x,y)|(y-x)(y-1/x)>=0},B={(x,y)|(x-1)^2+(y-1)^2 直线l与圆x^2+y^2+2x-4y+a=0(a