Question

equação do 2ª grau a) 3x²-7x + 2 =0 qual e a resposta ?

Answer 1

Equação do 2ª grau
a) 3x²-7x + 2 =0
a = 3; b = - 7; c = 2
/\= b^2 - 4ac
/\= (-7)^2 - 4.3.2
/\= 49 - 24
/\= 25
X = (- b +/- \/ /\)/2a
X = [-(-7)+/- \/25]/ 2.3
X = (7 +/- 5)/6

X ' = (7+5)/6=12/6= 2
X " = (7-5)/6= 2/6(:2)/(:2)= 1/3

R.: s ={ 2; 1/3)

Answer 2

$\sf3x^2-7x+2=0$

$\begin{cases}\sf a=3\\\sf b=-7\\\sf c=2\end{cases}$

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

$\sf\Delta=(-7)^2-4\cdot3\cdot2$

$\sf \Delta=49-24$

$\sf\Delta=25$

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

$\sf x=\dfrac{-(-7)\pm\sqrt{25}}{2\cdot3}$

$\sf x=\dfrac{7\pm5}{6}\begin{cases}\sf x_1=\dfrac{7+5}{6}=\dfrac{12}{6}=2\\\\\sf x_2=\dfrac{7-5}{6}=\dfrac{2}{6}=\dfrac{1}{3}\end{cases}$

$\boxed{\boxed{\sf S=\left\{\sf\dfrac{1}{3};2\right\}}}$