Answer:
s = - 1 ± 
Step-by-step explanation:
Given
s² + 2s - 6 = 0 ( add 6 to both sides )
s² + 2s = 6
To complete the square
add ( half the coefficient of the s- term )² to both sides
s² + 2(1)s + 1 = 6 + 1
(s + 1)² = 7 ( take the square root of both sides )
s + 1 = ±
( subtract 1 from both sides )
s = - 1 ± 
Thus
s = - 1 -
, s = - 1 + 
You would take 320 and multiply it by .60 and you would get 192. So the answer is B) $192.
It's a parabolic curve, so quadratic is best