Question 144703
{{{(6r^2st^3 - 9rs^2t^2)/(3rst)}}} is what I think you meant, although you actually wrote {{{6r^2st^3 - 9rs^2t^2/(3rst)}}}.


{{{(6r^2st^3 - 9rs^2t^2)/(3rst)}}}


{{{((3rst)2rt^2 - (3rst)3st)/(3rst)}}}


{{{(cross((3rst))2rt^2 - cross((3rst))3st)/cross((3rst))}}}


{{{2rt^2-3st}}}