Completing the Square

What value of c would make this a perfect square? $$x^2+8x+c$$

What value of c would make this a perfect square? $$x^2-6x+c$$ Options: 6, 3, 9, -6

What does (h,k) represent in the standard circle equation $$\left(x-h\right)^2+\left(y-k\right)^2=r^2$$ ?

What does the r represent in the standard equation of a circle? $$\left(x-h\right)^2+\left(y-k\right)^2=r^2$$

Find the center point and radius of this circle from the equation $$\left(x-4\right)^2+\left(y-3\right)^2=25$$

Standard form equation of a circle with center (7,0) and radius 3.

A circle has the equation $$x^2+y^2-4x+12y-8=0$$ . Use completing the square to write the equation in standard form.

A circle has the equation $$x^2+y^2-12x+8y+3=0$$ . Use completing the square to write the equation in standard form.

Complete the square to determine the equation of the circle in standard form: $$x^2+y^2+6x-12y+20=0$$

Complete the square to determine the equation of the circle in standard form: $$x^2+y^2+4x+6y-36=0$$