Complete the square to write the equation x^2 + y^2 – 4x – 16 = 0 in graphing form.

You can only ask one question at a
time.

For the equation x^2 + y^2 - 4x -16 =
0

We need to solve by completing the
square.

==> First we will group
terms.

==> x^2 - 4x + y^2 - 16 =
0

==> (x^2 -4x) + y^2 -16=
0

==> (x^2 -4x +4 -4) + y^2 -16=
0

==> (x-2)^2 -4 + y^2 =
16

==> (x-2)^2 + y^2 =
20

Then we have equation of a circle such
that:

(2, 0) is the center of
the circle and sqrt20 is the radius.