Strange Math 2.3

Question

Wow! You are amazing math tutors! I can't believe I'm actually doing well in math class. Though I could use your help again. I know I should be getting better, but there are so many factors that have kept me from properly studying. Today's assignment was seemingly impossible, but I'm sure you can solve it.

$1+5+6=-2-3$
$-2+7+9=4.5-1$
$1-6-9+14=1-2+7$
$2-23-1+438-216=\ ?$

Answer 1

The key word is

factors

and the pattern is

$x^2 + 5 x + 6$ has roots $-2, -3$;
$-2 x^2 + 7 x + 9$ has roots $4.5, -1$;
$x^3 - 6 x^2 - 9x + 14$ has roots $1, -2, 7$.

I'm not sure about the order, otherwise the answer could be

$0.5-4+6+9$.