Does the equation x2 - 4x + y2 = -3 intersect the x-axis?

To find out whether or not the equation x^2 - 4x + y^2 = -3 intersects the x-axis, we must set y = 0 in the equation (because at every point on the x-axis, y = 0). 

x^2 - 4x + 0 = -3

We then want to solve for x. We can do this by factoring.

x^2 - 4x + 3 = 0

By factoring...

(x - 3)(x - 1)

We can set each of these equations = 0 to solve where the function crosses the x-axis.

x - 3 = 0
x = 3

x - 1 = 0
x = 1

So we know at x = 1 and x = 3, the function x^2 - 4x + y^2 = -3 intersects the x-axis.