Question 915444
{{{-28a^5 - 42a^4 + 14a^3}}}
{{{-2*2*7*a^3*a^2-2*3*7*a^3*a+2*7*a^3}}}
{{{(-1)(2*7*a^3)2a^2+(-1)(2*7*a^3)3a+(2*7*a^3)}}}


The greatest common factor is {{{(2*7*a^3)}}}.
The OPPOSITE of the greatest common factor is {{{-2*7*a^3}}}.


Avoiding an intermediate step,
{{{highlight((-2*7*a^3)(2a^2+3a-1))}}}
and you could show this as:
{{{highlight(-14a^3(2a^2+3a-1))}}}