Question 419635
{{{(2y(4-x))/(y(x^2-16))}}}=
{{{(2y(4-x))/(y(x^2-4^2))}}}=
{{{(2y(4-x))/(y(x+4)(x-4))}}}=
{{{(-2y(x-4))/(y(x+4)(x-4))}}}=
{{{(-2)/(x+4)}}}