Выполните действия: 7a/(a^2-4b^2)-7/(a-2b).

\[\frac{7a}{a^{2} - 4b^{2}} - \frac{7}{a - 2b} =\]

\[= \frac{7a}{(a - 2b)(a + 2b)} - \frac{7^{\backslash a + 2b}}{a - 2b} =\]

\[= \frac{7a - 7a - 14b}{(a - 2b)(a + 2b)} =\]

\[= - \frac{14b}{a^{2} - 4b^{2}} = \frac{14b}{4b^{2} - a^{2}}.\]