The equation 4x2 + 8x + 15 = 0 is being rewritten in vertex form.
Fill in the missing step.
Given 4x2 + 8x + 15 = 0
Step 1 4(x2 + 2x ___) + 15 ___ = 0
Step 2 blank
Step 3 4(x + 1)2 + 11 = 0
A:4(x2 + 2x + 1) + 15 − 4 = 0
B: 4(x2 + 2x + 1) + 15 − 1 = 0
c: 4(x2 + 2x + 2) + 15 − 2 = 0
D: 4(x2 + 2x + 4) + 15 − 4 = 0