04.37. г) (3p+q)/(p^2-pq) - (3q+p)/(pq-q^2)

г) $$ \frac{3p+q}{p^2-pq} - \frac{3q+p}{pq-q^2} = \frac{3p+q}{p(p-q)} - \frac{3q+p}{q(p-q)} = \frac{q(3p+q) - p(3q+p)}{pq(p-q)} = \frac{3pq+q^2 - 3pq - p^2}{pq(p-q)} = \frac{q^2 - p^2}{pq(p-q)} = \frac{(q-p)(q+p)}{pq(p-q)} = -\frac{(p-q)(p+q)}{pq(p-q)} = -\frac{p+q}{pq} $$

Ответ: $$ -\frac{p+q}{pq} $$