Question

determine as raízes das equações
${x}^{2} + 12x - 189 = 0$

Answer 1

x² - 12x - 189 = 0

Δ = b² - 4 · a · c
Δ = (-12)² - 4 · 1 · (-189)
Δ = 144 + 756
Δ = 900

x = -b +- √Δ / 2 · a

x' = $\frac{12 + 30}{2}$ = $\frac{42}{2}$ = 21

x" = $\frac{12 - 30}{2} = \frac{-18}{2} = -9$