Answer:
B-at the second line
Step-by-step explanation:
hope it can help you lovelots
#LEARN WITH BRAINLY
[tex]x^2 +6x +18 =0\\\\\implies x^2 + 2 \cdot 3 \cdot x + 3^2 -3^2 +18 =0\\\\\implies (x+3)^2 -9 +18 =0\\\\\implies (x+3)^2 +9 =0\\\\\implies (x+3)^2 =-9[/tex]
