Respuesta :

[tex] \dfrac{7}{8} - \dfrac{1}{x} = \dfrac{3}{4} \\\\ \dfrac{7x - 8}{8x} = \dfrac{6x}{8x} \\\\ 7x - 8 = 6x \\\\ x = 8[/tex]

Answer : x = 8

Hope this helps. - M