Question

(x-1).(×-3)>0
×2-6×+8<0

Answer 1

$1 - ) \: \: (x -1 ) \times (x - 3) > 0 \\ {x}^{2} - 3x - x + 3 > 0 \\ {x}^{2} - 4x + 3 > 0 \\ \\ \\ \frac{ - b}{a} = \frac{4}{1} = 4 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \frac{c}{a} = \frac{3}{1} =3$

•Portanto, x' = 1; x" = 3

3 < x ou x < 1, consoante o gráfico anexado.



$2x - 6x + 8 < 0 \\ - 4x < - 8 \: \: \: \: \: \times ( - 1) \\ 4x > 8 \\ x > \frac{8}{4} \\ x > 2$