Question 103930
Let {{{y=x-2}}}


So we get 


{{{3y^2-3y-6}}}



*[invoke change_this_name4450 3, -3, -6, "y"]


Since {{{3y^2-3y-6}}} factors to {{{(3y-6)(y+1)}}} we can replace y with {{{y=x-2}}} to get 



{{{(3(x+2)-6)((x+2)+1)}}}