Question

3ײ+2×-1=0 equacao de 2grau​

Answer 1

$3x^2+2x-1=0$

$a=3\quad b=2\quad c=-1$

$\Delta=b^2-4\cdot a\cdot c$

$\Delta=2^2-4\cdot3\cdot(-1)$

$\Delta=4+12$

$\Delta=16$

$x=\dfrac{-b\pm\sqrt\Delta}{2\cdot a}$

$x=\dfrac{-2\pm\sqrt{16}}{2\cdot3}$

$x=\dfrac{-2\pm4}{6}\begin{cases}x'=\dfrac{-2+4}{6}=\dfrac{2}{6}=\dfrac{1}{3}\\\\x''=\dfrac{-2-4}{6}=-\dfrac{6}{6}=-1\end{cases}$

$\red{\boldsymbol{S=\{-1~;~1/3\} }}$