You need to work out the variables of 20 (the last number) first: 1, 2, 4, 5, 10, 20 Lets call these folks "p" At that point you need to work out the components of the main coefficient (the number before the most astounding force of x): 1 Lets call this person "q" At that point you need to make all the conceivable divisions you can with: ±p/q Since q is only 1, we are fortunate, so the conceivable normal roots are: ±1/1,±2/1,±4/1,±5/1.±10/1,±20/1