The answer is plus or minus 1,2,3,4,6,12, those are the possible rational xeros and we can find this if we take the leading coefficient 1 from x^4 and the constant 12
We now could use our p/q
P would be your 12 and your q would be 1
Now find the factors of 12 and 1
p/q= 12/1= 1,2,3,4,6,12 /1 (all plus or minus)
possible rational zeros 1,2,3,4,6,12 (all plus or minus) :)