can you help me understand the rational zeros theorem in this problem

use the rational zeros theorem to list all possible rational zeros of 
P(x)= 3x³ - 5x² + 4x - 2

When P(x) is in descending order, then:

The NUMERATOR of any rational zero must be a factor of the number
on the far RIGHT end, which is 2

The DENOMINATOR of any rational zero must be a factor of the number
on the far LEFT end, which is 3.

So the possible numerators are 1 and 2, because they are the only
positive integers that will divide evenly into 2.

The possible denominators are 1 and 3, because they are the only
positive integers that will divide evenly into 3.

So the possible fractions with numerator either 1 or 2 and 
denominator either 1 or 3 are

1/1, 1/3, 2/1, and 2/3.

However, these might be positive and they might be negative, 
so all the possible rational zeros are

±1/1, ±1/3, ±2/1, and ±2/3

Erasing the 1 denominators:

±1, ±1/3, ±2, and ±2/3

Edwin