[tex]5{x}^{2} - 13x - 3 = 3 \\ \Leftrightarrow 5 {x}^{2} - 13x - 6 = 0 \\ \Leftrightarrow 5 {x}^{2} - 15x + 2x - 6 = 0 \\ \Leftrightarrow 5x(x - 3) + 2(x - 3) = 0 \\ \Leftrightarrow (5x + 2)(x - 3) = 0 \\ \Leftrightarrow 5x + 2 = 0 \: \vee \: x - 3 = 0 \\ \Leftrightarrow x = - \frac{2}{5} \: \vee \: x = 3[/tex]
