So you can’t factor out the variables since one is d and the other is a. If they were the same letter you could factor them out as well The only number that goes into both 9 and 12 is three So divide by three essentially and take it out and place is next to the rest of the equation that is now in parenthesis 3(3d^3 - 4a^2)
Rewrite -12 as 4 x 3 and rewrite 9 as 3 x 3 which should give you something like this = 3 x 3d^3+4 x 3a^2 and then factor out the common term which is 3 and your answer should be this =3(3d^3-4a^2)
