Question 955087
{{{(w-3f)^2=(w-3f)(w-3f)}}}
{{{(w-3f)^2=(w-3f)w+(w-3f)(-3f)}}}
{{{(w-3f)^2=(w^2-3fw)+(-3fw+9f^2)}}}
{{{(w-3f)^2=w^2-6fw+9f^2}}}