how to solve; Xsq + ysq-4x=0

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

look like a circle to me.

To solve the equation x^2 + y^2 - 4x = 0, we can follow these steps:

Step 1: Rearrange the equation
First, rearrange the equation so that the x-terms are grouped together and the constant term is moved to the other side of the equation:
x^2 - 4x + y^2 = 0

Step 2: Complete the square
To complete the square, we want to rewrite the equation in the form (x - h)^2 + (y - k)^2 = r^2, where (h, k) represents the center of the circle and r represents the radius.

To do this, first complete the square for the x-terms:
x^2 - 4x = (x^2 - 4x + 4) - 4 = (x - 2)^2 - 4

Now, the equation becomes:
(x - 2)^2 - 4 + y^2 = 0

Step 3: Simplify
Combine like terms:
(x - 2)^2 + y^2 = 4

Step 4: Interpret the equation
The equation (x - 2)^2 + y^2 = 4 represents a circle with center (2, 0) and radius 2. The term (x - 2)^2 represents the horizontal shift of the circle's center, while y^2 represents the vertical shift. The constant 4 represents the square of the radius.

Therefore, the original equation x^2 + y^2 - 4x = 0 represents a circle with center (2, 0) and radius 2.