[tex] \frac{(27 - {b}^{3}) }{3b - 9} = \frac{(3 - b)(9 + 3b + {b}^{2}) }{ - 3(3 - b)} = - \frac{9 + 3b + {b}^{2} }{3} \\ [/tex]

[tex]b = 1[/tex]

[tex] - \frac{9 + 3b + {b}^{2} }{3} = - \frac{9 + 3 \times 1 + {1}^{2} }{3} = - \frac{9 + 3 + 1}{3} = - \frac{13}{3} = - 4 \frac{1}{3} \\ [/tex]