Answer:
1) 6(3x-2)
2) 24(x+2)
3) 9(5x−9) or 9(5x+9) if you meant to put addition.
4)8x+15
Yes
For example: Cut an apple into 9ths and another one into 8ths. Which has a bigger slice?
The given function is that is a cubic polynomial

when arranged in descending order that is from highest degree to lowest degree

Since it is a three degree polynomial it has three roots.
According to rational root theorem , the possible roots of the above expression that is factors of
=
are 
As you can see from the graph all roots of this polynomial are real.
The smallest positive root is 0.954 and smallest negative root are -0.724.