Question

resolva a equação do segundo grau sem usa bhaskara e sem usa soma e protudo:

2x²+6x-8=0​

Answer 1

$\Large\displaystyle\text{ \begin{gathered} \sf{ 2x {}^{2} +6x-8=0 } \end{gathered} }$

Substitui "1" no lugar do x:

$\Large\displaystyle\text{ \begin{gathered} \sf{ 2 \cdot1 {}^{2} + 6 \cdot1 - 8 = 0 } \end{gathered} }$

$\Large\displaystyle\begin{gathered} \sf{ 2 + 6 - 8 = 0 } \end{gathered}$

$\Large\displaystyle\begin{gathered} \sf{ 8 - 8 } \end{gathered}$

$\Large\displaystyle\begin{gathered} \sf{ 0 = 0 } \end{gathered}$

$\Large\displaystyle\text{ \begin{gathered} \boxed{ \sf{ x _{1} = 1}} \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{ x _{2} = \frac{c}{a} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \sf{ x _{2} = \frac{ - 8}{2} } \end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \boxed{\sf{ x _{2} = - 4} }\end{gathered} }$