[tex]Heya \:! \\ \\
given \: expression \: - \\ \\ \frac{7x + 21}{ {x}^{2} + 5x + 6} \div \frac{x + 6}{x + 2} \\ \\ \\ \frac{7x + 21}{ {x}^{2} + 5x + 6} \times \frac{x + 2}{x + 6} \\ \\ \\ \frac{7(x + 3)}{(x + 3)(x + 2)} \times \frac{(x + 2)}{(x + 6)} \\ \\ \\ = \frac{7}{(x + 6)} \: \: \: \: \: ans.[/tex]
