Question

Equação Conpleto do 2⁰ grau x²+4x-5=0

Answer 1

$x^2+4x-5=0$

$a=1\quad b=4\quad c=-5$

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

$\Delta=4^2-4\cdot1\cdot(-5)$

$\Delta=16+ 20$

$\Delta= 36$

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

$x=\dfrac{-4\pm\sqrt{36}}{2\cdot1}$

$x=\dfrac{-4\pm6}{2}\begin{cases}x_1=\dfrac{-4+6}{2}=\dfrac{2}{2}=1\\\\x_2=\dfrac{-4-6}{2}=-\dfrac{10}{2}=-5\end{cases}$

$\red{\boldsymbol{S=\{-5\,;\,1\} }}$