Step-by-step explanation:
[tex]bg + 9f = 27 \\ [/tex]
[tex]bg + 9f - 9f = 27 - 9f[/tex]
[tex]bg = 27 - 9f[/tex]
[tex]bg \div b = \frac{27 - 9f}{b} [/tex]
[tex]g= \frac{27 - 9f}{b} [/tex]
