Question

questão de prova me ajudem por favor amigos ♡

Answer 1

7x² - 9x - 2 = 0 

delta = (-9)² - 4 . 7 . (-2) 
delta = 81 + 56
delta = 137 

x = -(-9) +- √137 / 2.7
x = 9 +- √137 / 14

Answer 2

$7x^2 - 9x - 2 = 0$

Resolvendo por Bháskara:

a=7, b=−9, c=−2

Δ=b²−4ac
Δ=(−9)²−4*(7)*(−2)
Δ=81+56
Δ=137

$x = \dfrac{-b \pm \sqrt{b^2 -4*a*c}}{2*a}$

$x = \dfrac{-b \pm \sqrt{\triangle}}{2*a} \\ \\ \\ x = \dfrac{-(-9) \pm \sqrt{137}}{2*7} \\ \\ \\ x = \dfrac{9 \pm \sqrt{137}}{14} \\ \\ \\ x' = \dfrac{9 + \sqrt{137}}{14} \\ \\ \\ x'' = \dfrac{9 - \sqrt{137}}{14}$


S = {$\dfrac{9 + \sqrt{137}}{14}, \ \ \dfrac{9 - \sqrt{137}}{14}$}