Question 904046
{{{n<0}}};
{{{n(-4+2n)=336}}}
{{{n(2n-4)=336}}}
{{{2*n(n-2)=336}}}
{{{n(n-2)=168}}}
{{{n^2-2n-168=0}}}


168=6*28=2*3*4*7=12*14


The quadratic member is factorable.
{{{(n+12)(n-14)=0}}}


We want the negative number as specified in the description, so {{{highlight(n=-12)}}}.