Сократите дробь: (9x^2+6xy+y^2)/(9x^2-y^2).

\[\frac{9x^{2} + 6xy + y^{2}}{9x^{2} - y^{2}} =\]

\[= \frac{(3x + y)^{2}}{(3x - y)(3x + y)} = \frac{3x + y}{3x - y}.\]