how to verify asymptotic upper bound ( substitution method) $T(n)= 4T(n/2 +2)+n$

Question

i guess $O(n^2)$ and $T(n)= 4C(n/2+2)^2 - C(n/2+2) +n$ ...(??) $\leq C(n^2)$

is this right? and how can i verify this problem using the substitution method... help me