Answer:
 [1] = 6
 x = -3/2 is the root
Explanation:
A perfect square trinomial is of the form ...
 (a + b)² = a² +2ab +b²
You have ... 
- a²=16w² ⇒ a = 4w
 - b² = 36 ⇒ b = 6
 - 2ab = 2(4w)(6) = 48w
 
Then the factorization is ...
 16w² +48w +36 = (4w +6)²
This will be zero when x = -6/4 = -3/2.