Answer
$\color{blue}{\dfrac{6}{p-q}}$
Work Step by Step
Factor out $-1$ in the denominator of the subtrahend to obtain:
$=\dfrac{4}{p-q} - \dfrac{2}{-1(-q+p)}
\\=\dfrac{4}{p-q} - \dfrac{-2}{p-q}$
The expressions are similar so subtract the numerators and copy the denominator to obtain:
$=\dfrac{4-(-2)}{p-q}
\\=\dfrac{4+2}{p-q}
\\=\color{blue}{\dfrac{6}{p-q}}$
