Question

Resolva (x+1)² = 4x+4

Answer 1

(x + 1)² = 4x + 4
(x + 1) . (x + 1) = 4x + 4
x² + x + x + 1² = 4x + 4
x² + 2x + 1 = 4x + 4
x² + 2x - 4x + 1 - 4 = 0
x² - 2x - 3 = 0
Δ = b² - 4 . a . c
Δ = (- 2)² - 4 . 1 . (- 3)
Δ = 4 + 12
Δ = 16

x = (- b ± √Δ)/2 . a
x = (- (- 2) ± √16)/2 . 1
x = (2 ± 4)/2

x' = (2 + 4)/2
x' = 6/2
x' = 3

x'' = (2 - 4)/2
x'' = - 2/2
x'' = - 1