Question

2x ao quadrado -x-6=0
Usando fórmula de Bhaskara​

Answer 1

$2x^2-x-6=0$

$a=2\quad b=-1\quad c=-6$

$x=\dfrac{-b\pm\sqrt{b^2-4\cdot a\cdot c}}{2\cdot a}$

$x=\dfrac{-(-1)\pm\sqrt{(-1)^2-4\cdot2\cdot(-6)}}{2\cdot2}$

$x=\dfrac{1\pm\sqrt{1+48}}{4}$

$x=\dfrac{1\pm\sqrt{49}}{4}$

$x=\dfrac{1\pm7}{4}\begin{cases}x' =\dfrac{1+7}{4}=\dfrac{8}{4}=2\\\\x''=\dfrac{1-7}{4}=-\dfrac{6}{4}= -\dfrac{3}{2}\end{cases}$

$\red{\boldsymbol{ S=\{-3/2\;;\;2\}}}$