1.5X = 9%; this reads 150% of X (1.5X) equals 9%: 150% of X is the same as X increasing by 50%.
X = 9/1.5;divide by 1.5
X = 6
1) not sure of an example but it will be something with exponential growth.
2) Constant rate of change means the slope is the same between every point (always represented by a straight line). Average rate of change is the slope between the first and last point (not usually represented by a straight line).
3) g(x) = 3(2ˣ) - 6
g(0) = 3(2°) - 6 = 3(1) - 6 = 3 - 6 = -3 ⇒ coordinate (0, -3)
g(3) = 3(2³) - 6 = 3(8) - 6 = 24 - 6 = 18 ⇒ coordinate (3, 18)
average rate of change (slope) from x = 0 to x = 3: 

= 
= 7
X² - 8x = 9
x² - 8x - 9 = 0
x² + x - 9x - 9 = 0
x(x + 1) -9(x + 1) = 0
(x+1)(x-9) = 0
x = -1 or 9
In short, Your Answers would be -1 & 9
Hope this helps!
The answer i found to be is C