Answer:
Choice B is the answer.
Explanation:
We have given two step.
(x+b/2a)² = b²-4ac / 4a² Step I
a+b/2a = ±√b²-4ac / 4a² Step II
We have to choose the method to move step I to step II.
Taking square root to both sides of step I, we have
√(x+b/2a)² = √b²-4ac/4a²
As we know that
√x² = ±x
(x+b/2a) = ±√b²-4ac / 4a² and we get the step II.
Hence, the answer is choice B.