Question

Aplicando a fórmula de Bhaskara, resolva as seguintes equações: a) 3x² – 7x + 4 = 0 b) 9y² – 12y + 4 = 0​

Answer 1

Explicação passo-a-passo:

a) $3x^2-7x+4=0$

$\Delta=(-7)^2-4\cdot3\cdot4$

$\Delta=49-48$

$\Delta=1$

$x=\dfrac{-(-7)\pm\sqrt{1}}{2\cdot3}$

$x=\dfrac{7\pm1}{6}$

$x'=\dfrac{7+1}{6}~\Rightarrow~x'=\dfrac{8}{6}~\Rightarrow~\boxed{x'=\dfrac{4}{3}}$

$x"=\dfrac{7-1}{2}~\Rightarrow~\boxed{x"=1}$

b) $9y^2-12y+4=0$

$\Delta=(-12)^2-4\cdot9\cdot4$

$\Delta=144-144$

$\Delta=0$

$y=\dfrac{-(-12)\pm\sqrt{0}}{2\cdot9}$

$y=\dfrac{12\pm0}{18}$

$y'=y"=\dfrac{12}{18}~\Rightarrow~\boxed{y'=y"=\dfrac{2}{3}}$