Yes, your work is correct.
The diagram does illustrate x²+6x+9=72. This is also represented by
(x+3)² = 72
We can take the square root of both sides:

When we evaluate this, the answers are x = -11.5 or x = 5.5.
Answer:
Your second listed answer choice would be your answer.
Answer:
600 ÷ 4 = 150
450 ÷ 3 = 150
The same thing either way.
They are considered proportional ratios
The answer is D but i could be wrong