Answer
$\dfrac{6}{p-q}$
Work Step by Step
The given expression, $
\dfrac{4}{p-q}-\dfrac{2}{q-p}
,$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{4}{p-q}-\dfrac{2}{-(p-q)}
\\\\=
\dfrac{4}{p-q}+\dfrac{2}{p-q}
.\end{array}
Since the fractions are similar, then copy the common denominator and add/subtract the numerators. Hence, the expression, $
\dfrac{4}{p-q}+\dfrac{2}{p-q}
,$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{4+2}{p-q}
\\\\=
\dfrac{6}{p-q}
.\end{array}
