Question

Valor de X? 15 = x(ao quadrado) - 4x +3​

Answer 1

Resposta:

x² - 4x + 3 = 15

Some "1" de ambos os lados

x² - 4x + 4 = 16

(x-2)² = 4²

x - 2 = +/- 4

x' = 6

x'' = -2

**********************************************

Usando Bhaskara:

x² - 4x + 3 = 15

x² - 4x - 12 = 0

Δ = b² - 4ac = (-4)² - 4*1*(-12)

Δ = 64

x' = (-b+√Δ)/2a

x' = (4+√64)/2 = (4+8)/2

x' = 6

x'' = (-b-√Δ)/2a

x'' = (4-√64)/2 = (4-8)/2

x'' = -2