Question

Resolva (x-2) x (x+1) = 3

Answer 1

Vamos lá :

(x - 2)(x + 1) = 3
x² + x - 2x - 2 = 3
x² - x - 2 - 3 = 0
x² - x - 5 = 0

a = 1 ; b = - 1 ; c = - 5

Δ = b² - 4ac
Δ = (-1)² - 4.1.(-5)
Δ  = 1 + 20
Δ   = 21

Bhaskara :

x = - b +/- √Δ / 2a
x = -(-1) +/- √21 /2.1
x = 1 +/- √21 / 2

x' = (1 - √21) / 2
x'' = (1 + √21) / 2

S = {1 -√21 /2  , 1 + √21 / 2 }

Espero ter ajudado !!!