Question

ninguém tá conseguindo fazer esse :

X² - x - 12 = 0

Answer 1

$x= \frac{-(-1)\pm \sqrt{(-1)^2-4(-12)} }{2}= \frac{1\pm7}{2}$

$x_{1}= \frac{1-7}{2}=- \frac{6}{2}=-3$

$x_{2}= \frac{1+7}{2}=\frac{8}{2}=4$

$S=\{-3,4\}$