Answer:
3.5
Step-by-step explanation:
The vertex form:

(h,k) - the coordinates of the vertex

The coordinates of the vertex are
(-4,13).
Pls. see attachment. I created that table for easy monitoring and understanding.
Yellow cells are sums that are even.
Orange cell are sums that are multiples of 3.
Yellow cells w/ orange texts are sums that are both even and multiples of 3.
Answer:
GRRAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAPEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE
Step-by-step explanation: