Circles Test 2...

A circle has a diameter whose ends are at (-3, 2) and (12, -6) Its Equation is

Find the equation of a circle with center $$(0, 0)$$ and radius $$5$$.

What is the radius of the circle with the following equation?
$$\displaystyle x^{2}-6x+y^{2}-4y-12=0$$

The circle with radius $$1$$ and centre being foot of the perpendicular from $$(5, 4)$$ on y-axis, is?

Equation of the circle with centre on y-axis and passing through the points $$(1,0),(1,1)$$ is:

Centres of the three circles
$${x}^{2}+{y}^{2}-4x-6y-14=0$$ 
$${x}^{2}+{y}^{2}+2x+4y-5=0$$ and
$${x}^{2}+{y}^{2}-10x-16y+7=0$$. The centres of the circles are:

Centre of circle whose normal's are $$x^{2}-2xy-3x+6y=0$$, is 

The equation of the circle passing through $$(3, 6)$$ and whose centre is $$(2, -1)$$ is 

The radius of the circle centred at $$(4,5)$$ and passing through the centre of the circle $${x}^{2}+{y}^{2}+4x+6y-12=0$$ is

The centre of the circle $$x^2+y^2+10x-20y+100=0$$ is