Question

(×-2) . (×+2) = 2 . (×+4)

Answer 1

(x - 2).(x + 2) = 2.(x + 4)
x² + 2x - 2x - 4 = 2x + 8
x² - 4 = 2x + 8
x² - 2x - 8 - 4 = 0
x² - 2x - 12 = 0

Δ = b² - 4.a.c 
Δ = -2² - 4 . 1 . -12 
Δ = 4 - 4. 1 . -12 
Δ = 52

Há 2 raízes reais.

x = (-b +- √Δ)/2a

x' = (--2 + √52)/2.1   
x'' = (--2 - √52)/2.1

x' = 9,21110255092798 / 2   
x'' = -5,211102550927978 / 2

x' = 4,60555127546399   
x'' = -2,605551275463989