Question

40 = 35 - 4 x (x + 6)

Answer 1

$40 = 35 - 4 {x}^{2} - 24x$

$4 {x}^{2} + 24x + 5 = 0$

$x = \frac{ - 24\pm \sqrt{ {24}^{2} - 4 \times 4 \times 5 } }{8}$

$x = \frac{ - 24\pm \sqrt{576 - 80} }{8}$

$x = \frac{ - 24\pm \sqrt{496} }{8}$

$x = \frac{ - 24 + 4\sqrt{31} }{8} \\ \\ x = \frac{ - 24 - 4 \sqrt{31} }{8}$

$x = \frac{ - 6 + \sqrt{31} }{2} \\ \\ x = \frac{ - 6 - \sqrt{31} }{2}$