Question

x(x-2)=2(x+6) equação

Answer 1

$x(x - 2) = 2(x + 6) \\ {x}^{2} - 2x = 2x + 12 \\ {x}^{2} - 4x - 12 = 0 \\ \\ {b}^{2} - 4ac = {( - 4)}^{2} - 4 \times 1 \times ( - 12) = \\ 16 + 48 = 64 \\ \\ x = \frac{ - ( - 4) + \sqrt{64} }{2 \times 1} \\ x = \frac{4+ 8}{2} = \frac{12}{2} = 6 \\ \\ \frac{ - ( - 4)- \sqrt{64} }{2 \times 1} \\ x = \frac{4 - 8}{2} = \frac{ - 4}{2} = - 2$