\[\frac{8a - 3}{a + 5} - \frac{40 - 27a}{a^{2} + 2a - 15} =\]
\[= \frac{8a - 3^{\backslash a - 3}}{a + 5} - \frac{40 - 27a}{(a + 5)(a - 3)} =\]
\[= \frac{8a^{2} - 3a - 24a + 9 - 40 + 27a}{(a + 5)(a - 3)} =\]
\[= \frac{8a^{2} - 31}{a^{2} + 2a - 15}\]
\[a^{2} + 2a - 15 = 0\]
\[a_{1} + a_{2} = - 2;\ \ \ \ a_{1} \cdot a_{2} = - 15\]
\(a_{1} = - 5;\ \ \ a_{2} = 3.\)