x^2+y^2-4x-2y+5=0,则log2(1/5)=错了，是则logx(y)^x的值时

已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 若|2x-y|+(x-2y-4）2=0则（x-y）2=（ ）l 若lx-3l+ly-2l=0,则x+y= ,x-y= 若(x+y-5)^2+lx-y+3l=0x^2-y^2=? lx-y+3l+（x+y）^2=0,则x+3y块 绝对值若lx-2y+1l+lx+y-5l=0则x=y= (2009.呼和浩特)若lx-2y+1l+l2x-y-5l=0,则x+y= 若(x+y-5)^2+lx-y+3l=0,则 x^2-y^2=?,现在回答, x*x+2x+y*y-4y+5=0 x= y= 直线L将圆x+y-2x-4y=0平分,且与直线x+2y=0垂直.则直线L的方程为? l 3x -2y-4.5 l +√5x+3y-45.5 =0 求4x＋7y的平方根 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 l x-3l与I 2y+3I互为相反数则x+y= 直线l与圆x^2+y^2+2x-4y+a=0(a 直线L与圆X^2+Y^2+ 2x-4Y+a=0(a 直线l与圆x^2+y^2+2x-4y+a=0(a 直线l与圆x²+y²+2x-4y+a=0（a 已知x^2+y^2-4x+2y+5=0则x^y=?