A. (x2+y2+x+3y)+λ(2x+3y+3)=0

B. 3(x2+y2+x+3y)+λ(x+y+3)=0

C. 3(x2+y2-x-3y)+λ(x-y-3)=0

D. 3(x2+y2+2x+3y)+3λ(2x+3y+63)=0

The circle described on the line joining the points (0, 1), (a, b) as diameter cuts the x-axis in points whose abscissa are roots of the equation

If the length of the tangent from (h, k) to the circle x^{2}+y^{2}=16 is twice the length of the tangent from the same point to the circle x^{2}+y^{2}+2x+2y=0, then

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

The equation of the circle passing through the points of intersection of the circlesx2+y2=5, x^{2}+y^{2}+12x+8y-33=0 and touching x-axis is

If 4y=x+7 is diameter of the circumscribing circle of the rectangle ABCD and A(-3, 4), B(5, 4), then the area of the rectangle is