Here are two steps from the derivation of the quadratic formula.
x² + b10
2a
=
b
+
a 2a
b
(x + 2)² --- + ( 2 )²
2a
a 2a
What took place between the first step and the second step?
OA. Factoring a perfect square trinomial
OB. Taking the square root of both sides
OC. Completing the square