To write the given quadratic equation to its vertex form, we first form a perfect square.
 
 x² - 2x + 5 = 0
Transpose the constant to other side of the equation,
 x² - 2x = -5
Complete the square in the left side of the equation,
 x² - 2x + (-2/1(2))² = -5 + (-2/1(2))² 
Performed the operation,
 x² - 2x + 1 = -5 + 1
Factor the left side of the equation,
 (x - 1)² = -4
Thus, the vertex form of the equation is,
  (x-1)² + 4 = 0