[tex]answer = \frac{ {(2a + 1)}^{2} }{50a} \\ solution \\ \frac{2a + 1}{10a - 5} \div \frac{10a}{ {4a}^{2} - 1 } \\ = \frac{2a + 1}{10a - 5} \times \frac{ {4a}^{2} - 1}{10a} \\ = \frac{2a + 1}{5(2a - 1)} \times \frac{ {4a}^{2} - {(1)}^{2} } {10a} \\ = \frac{2a + 1}{5(2a - 1)} \times \frac{(2a - 1)(2a + 1)}{10a} \\ = \frac{ {(2a + 1)}^{2} }{50a} \\ hope \: it \: helps[/tex]
