Réponse :

bonjour,

reponse ci jointe

bjr

(3x-1) / (x+7) = 1/4x

donc

3x-1 = 1/4x (x+7)

3x - 1 = 1/4x² + 7/4x

1/4x² + 7/4x - 3x + 1 = 0

1/4x² - 5/4x + 1 = 0

soit

x² - 5x + 4 = 0

Δ = (-5)² - 4*1*4 = 25 - 16 = 9 = 3²

x' = (5 - 3) / 2 = 1

et

x'' = (5 + 3) / 2 = 4