Question

a)x^2 - 7x + 4 = 0



pf
rapido

Answer 1

Resposta:

$\boxed{x_1=\dfrac{7+\sqrt{33}}{2}}\\\\\boxed{x_2=\dfrac{7-\sqrt{33}}{2}}$

Explicação passo-a-passo:

Para resolver basta aplicar a fórmula resolutiva, então:

x² - 7 x + 4 =0  

a = 1,  b = -7, c = 4

Fórmula:

$x=\dfrac{-b\pm\sqrt{b^2 - 4\times a\times c}}{2\times a}\\\\x=\dfrac{-(-7)\pm\sqrt{(-7)^2 - 4\times 1\times 4}}{2\times 1}\\\\x=\dfrac{+7\pm\sqrt{49 - 16}}{2}\\\\x=\dfrac{7\pm\sqrt{33}}{2}\\\\\boxed{x_1=\dfrac{7+\sqrt{33}}{2}}\\\\\boxed{x_2=\dfrac{7-\sqrt{33}}{2}}$

${\begin{center}\fbox{\rule{3ex}{2ex}\hspace{19.3ex}{#ESPERO TER AJUDADO !}\hspace{19.3ex}\rule{3ex}{2ex}}}{\end{center}$

$\fbox{{\begin{minipage}[t]{0.89\textwidth{ }}\sc{Escolha\ a\ melhor\ resposta\ entre\ as\ obtidas\ e\ voc{\^{e}}\ receber{\'{a}}\ 25\%\ dos\ pontos\ que\ voc\^{e}\ gastou\ para\ a\ sua\ pergunta.}\end{minipage}{ }}}$