Question

Solve the inequation $x^2-2x-63<0$

Answer 1

$x^2-2x-63<0$
$x^2-9x+7x-63<0$
$x(x-9)+7(x-9)<0$
$(x-9)(x+7)<0$
$x-9<0$ and $x+7>0\Rightarrow x<9$ and $x>-7$ or
$x-9>0$ and $x+7<0$
$x>9$ and $x<-7$
$\therefore$ Solution set is $\{x/-7<x<9\}$