[tex](4x - \frac{1}{2} )(4x + \frac{1}{2} ) = {(4x)}^{2} - {( \frac{1}{2}) }^{2} = {16x}^{2} - \frac{1}{4} \\ \\ ( \sqrt{5} + 5)( \sqrt{5} + 5) = 5 + 5 \sqrt{5} + 5 \sqrt{5} + 25 = 30 + 10 \sqrt{5} \\ \\ (3x - 4)(4 - 3x) = {(3x)}^{2} - {4}^{2} = {9x}^{2} - 16[/tex]