Exercício Resolvido de Equações do 2.º Grau
a)
\( \displaystyle x^{2}-5x+6=0 \)
Calculando Δ
\[ \bbox[#99CCFF,10px]
{\Delta =b^{2}-4ac}
\]
\[
\begin{align}
&\Delta =(-5)^{2}-4.1.6\\
&\Delta =25-24\\
&\Delta=1
\end{align}
\]
Cálculo das raízes
\[ \bbox[#99CCFF,10px]
{x_{1,2}=\frac{-b\pm \sqrt{\Delta \;}}{2a}}
\]
\[
\begin{align}
& x_{1,2}=\frac{-(-5)\pm\sqrt{1\;}}{2.1}\\
& x_{1,2}=\frac{5\pm1}{2}\\
& x_{1}=\frac{5+1}{2}=\frac{6}{2}=3\\
& x_{2}=\frac{5-1}{2}=\frac{4}{2}=2
\end{align}
\]
\[ \bbox[#FFCCCC,10px]
{V=\{3,2\}}
\]