The first step we take is to factor out a GCF:
2d(d³ + 3d² - 9d - 27)
Now, we can factor what's in the parenthesis by grouping (don't forget to keep the 2d we factored out):
2d[d²(d+3) -9(d+3)]
2d(d²-9)(d+3)
d²-9 can still be factored because it is the difference of two squares:
2d(d+9)(d-9)(d+3)
That is the completely factored form.
