Answer:
s ≈ - 0.5 , s ≈ 8.5
Step-by-step explanation:
s² - 8s - 4 = 0 ( add 4 to both sides )
s² - 8s = 4
To complete the square
add ( half the coefficient of the s- term )² to both sides
s² + 2(- 4)s + 16 = 4 + 16
(s - 4)² = 20 ( take square root of both sides )
s - 4 = ± ( add 4 to both sides )
s = 4 ±
Then
s = 4 - ≈ - 0.5 ( to the nearest tenth ) ← smaller solution
s = 4 + ≈ 8.5 ( to the nearest tenth ) ← larger solution