Question 69196
{{{ 6b^2c-12b^2c^3+3b^3c^2 }}}
Look for each factor in turn. Firstly what is the common factor of 6, 12 and 3. 
Then look for a common factor from {{{b^2}}}, {{{b^2}}} and {{{b^3}}}
Now look for the common factor from{{{c}}}, {{{c^3}}} and {{{c^2}}}
This gives a common factor of {{{3b^2c}}}

{{{ 6b^2c-12b^2c^3+3b^3c^2=3b^2c(2-4c^2+bc) }}}