Ответ:

[tex]2.[/tex]

Объяснение:

[tex] \displaystyle \frac{4 {x}^{2} - x}{ {x}^{2} - 9} \times \frac{x + 3}{4x - 1} = \frac{x(4x - 1)}{(x - 3)(x + 3)} \times \frac{x + 3}{4x - 1} = \frac{x}{x - 3} .[/tex]

При х = 6:

[tex] \dfrac{6}{6 - 3} = \dfrac{6}{3} = 2.[/tex]