Сократите дробь 9q-q_________9p^2+6pq+q^2

\frac{ 9p^{2}- q^{2} }{ 9p^{2} +6pq+ q^{2} } = \frac{(3p-q)(3p+q)}{ (3p+q)^{2} } = \frac{3p-q}{3p+q}