Question

resolva as equacoes do 2 grau
x2 + 5x + 8 = 4

Answer 1

x² + 5x + 8 = 4
x² + 5x + 8 - 4 = 0
x² + 5x + 4 = 0

Δ = b² - 4.a.c 
Δ = 5² - 4 . 1 . 4 
Δ = 25 - 4. 1 . 4 
Δ = 9

Há 2 raízes reais.

x = (-b +- √Δ)/2a

x' = (-5 + √9)/2.1   
x'' = (-5 - √9)/2.1

x' = -2 / 2   
x'' = -8 / 2

x' = -1   
x'' = -4