Find equation of circle concentric with circle `4x^2+4y^2 - 12x-16y-21 = 0` and of half its area.

Find the equation of a circle concentric with the circle : 2x^2 + 2y^2-6x+8y+1=0 and of double its area.

Find the equation of a circle concentric with the circle 2x^2+2y^2-6x+8y+1=0 and of double its area.

The equation of circle concentric with circle x^2+y^2-6x+ 12y+ 15=0 and double its area is

Find the equation of the circle concentric with the circle x^2+y^2-6x+12y+15 = 0 and double of its area

Find the equation of the circle concentric with the circle 2x^2 + 2y^2 - 6x + 8y+1=0 and of double its area.

Find the equation of the circle concentric with the circle 2x^2 + 2y^2 - 6x + 8y+1=0 and of double its area.

The equation of circle concentric with circle x^(2)+y^(2)-6x+12y+15=0 and double its area is

Find the equation of a circle concentric with the circle x^2 + y^2-2x -4y + 1 = 0 and whose radius is 5.

Find the equation of the circle concentric with the circle 2x^2+2y^2-8x+10y-39=0 and having its area 16pi sq.units