Grouping, looking at the coefficients (2,-7,-4, and 14) you notice that 2,-4, and 14 are all factors of 2, however you also notice that -7 and 14 arefactors of 7, so you want to group the terms containing -7 and 14 up (and 2 and -4 together)
so rearranging stuff 2x^3 -4x -7x^2+14
grouping (2x^3-4x) + (-7x^2+14)
factoring stuff, (reverse distribution process) notice you can factor out a 2x from the first group, and a -7 from the 2nd group, hence you will get
2x(x^2-2) -7(x^2-2)
you can factor out the (x^2-2) from both terms, hence you are left with