Question

x ao quadrado-3x-2=0?

Answer 1

x² - 3x - 2 = 0

a  = 1
b = -3
c = -2

Δ = b² - 4ac
Δ = (-3)² - 4.(1).(-2)
Δ = 9 + 8
Δ = 17

$x = \dfrac{-b \frac{+}{-} \sqrt{b^2-4ac} }{2a}$

$x = \dfrac{-(-3) \frac{+}{-} \sqrt{b^2-4ac} }{2a}$

$x = \dfrac{3 \frac{+}{-} \sqrt{17} }{2}$

$x' = \dfrac{3+ \sqrt{17} }{2}$

$x" = \dfrac{3- \sqrt{17} }{2}$