Start with a quadratic expression in the form ax^2 + bx + c
If a ≠ 1, factor out a from the x^2 and x terms
Take the coefficient of x
Divide it by 2
Square the result
Add and subtract that square inside the expression
Rewrite the first three terms as a perfect square trinomial
Factor the perfect square trinomial into binomial squared form
Simplify the remaining constant terms
Write the final expression in completed square form a(x + h)^2 + k