[tex] \frac{5}{6} x + 16 = \frac{4}{9} x + 9 \\ 16 - 9 = \frac{4}{9} x - \frac{5}{6} x \\ 7= \frac{8}{18} x - \frac{15}{18} x = - \frac{7}{15}x \\ x = \frac{7}{ - \frac{7}{15} } = - \frac{105}{7} \\ x = - 15[/tex]