((2 4 x 3 + 2 6 x 2) - 9x) - 36 Step 3 : Checking for a perfect cube : 3.1 16x 3 +64x 2-9x-36 is not a perfect cube . Trying to factor by pulling out : 3.2 Factoring: 16x 3 +64x 2-9x-36 Thoughtfully split the expression at hand into groups, each group having two terms : Group 1: -9x-36 Group 2: 16x 3 +64x 2 Pull out from each group separately :