The answer to your question is k (-3) = 21!
Here's how I got this answer:
K(a) = 2a^2 - a
K(a) = 2a^2 - a K(-3) = 2(-3)^2 - (-3)
K(a) = 2a^2 - a K(-3) = 2(-3)^2 - (-3)K(-3) = 2(9) + 3
K(a) = 2a^2 - a K(-3) = 2(-3)^2 - (-3)K(-3) = 2(9) + 3K (-3) = 18 + 3
K(a) = 2a^2 - a K(-3) = 2(-3)^2 - (-3)K(-3) = 2(9) + 3K (-3) = 18 + 3K (-3) = 21
I hope this helps!
Also sorry for the late answer, I just got the notification that you replied to my comment, I hope I came in time!
