Найдите значение выражения [latex] \frac{ a^{2}-25 }{2 a^{2} } * \frac{a}{ a-4} [/latex] при α=[latex] \frac{1}{23} [/latex]

[latex] \frac{ a^{2}-25 }{2 a^{2} } \cdot\frac{a}{ a-4} = \frac{ (a^{2}-25)a }{2 a^{2}(a-4) }= \frac{ a^{2}-25 }{2a(a-4) }= \frac{ ( \frac{1}{23} )^{2}-25 }{2\cdot\frac{1}{23}(\frac{1}{23}-4) }= \frac{ \frac{1}{529} - \frac{13225}{529} }{\frac{2}{23}(\frac{1}{23}- \frac{92}{23} ) }= \\\ = \frac{ - \frac{13224}{529} }{- \frac{182}{529} }= \frac{13224}{182} = \frac{6612}{91} [/latex]