Question 58791
{{{-16x^4/-24x^2}}}  <---is this what you meant?
If so the exponents only have x's as there base.  Reduce the numbers as usual.
{{{(-16/-24)*(x^4/x^2)}}}
{{{(2/3)*(x^4/x^2)}}}
{{{2x^4/3x^2}}}  When dividing subtract the exponents of like bases.
{{{2x^(4-2)/3}}}
{{{highlight(2x^2/3)}}}
Happy Calculating!!!