Answer:
x = 3 ± 
Step-by-step explanation:
x² - 6x - 4 = 0 ( add 4 to both sides )
x² - 6x = 4
To complete the square
add ( half the coefficient of the x- term)² to both sides
x² + 2(- 3)x + 9 = 4 + 9
(x - 3)² = 13 ( take square root of both sides )
x - 3 = ±
( add 3 to both sides )
x = 3 ± 
If it can scan 72 photos in 8 minutes, it can scan 72/8 = 9 photos per minute.
So in 23 minutes, it can scan 9x23 = 207 photos
The answer would be 0.37.
The answer is because 3 squared =9
45 - 35 = 10
so we divide by 4 10/4 = 2.5
The sequence is 35, 37.5, 40, 42.5, 45