[tex] \frac{( {a}^{2} - a)x}{ {x}^{2} - 4 } = \frac{a}{x + 2} \times \frac{6}{x - 2} \\ \\ \frac{( {a}^{2} - a)x}{ {x}^{2} - 4 } = \frac{6a}{ {x}^{2} - 4} [/tex]
[tex]( {a}^{2} - a)x = 6a \\ \\ ax(a - 1) = 6a \\ \\ x = \frac{6a}{a(a - 1)} \\ \\ x = \frac{6}{a - 1} [/tex]