Answer:
The answer to your question is Center = (-1, 2) Radius = 2
Explanation:
Data
x² + y² + 2x - 4y + 1 = 0
Process
1.- Group like terms
(x² + 2x ) + (y² - 4y ) = -1
2.- Complete Perfect square trinomials
(x² + 2x + 1²) + (y² - 4y + 2²) = -1 + 1² + 2²
3.- Simplify
(x + 1)² + (y - 2)² = 4
4.- Get the center and the radius
Standard equation (x - h)² + (y - k)² = r²
Center = (h, k)
Center = (-1, 2)
Radius = 2