Question 901776
72c^2 + {{{  highlight_green(24c) }}}  - 16 = (12c - 4)(6c+4)
Why?  Check with FOIL
F	First terms 72c^2
O	Outside terms 48c
I	Inside terms  -24c    Note(48c-24c = {{{  highlight_green(24c) }}} )
L	Last terms -16