Réponses

Meilleure réponse !
2012-10-14T14:08:00+02:00

Hello,

 

8/x = (8+x)/8

8/x - (8+x)/8 = 0

64/8x - [(8+x)x]/8x = 0

64/8x - (8x + x²)/8x = 0

(64 - 8x - x²)/8x = 0

64 - 8x - x² = 0

delta = b² - 4ac

delta = 64 - 4*64*(-1)

delta = 320 

 

x1 = (8+V320)/-2 = -4-4V5

x2 = (8-V320)/-2 = -4+4V5

 

S = {-4-4V5 ; -4+4V5}

 

Au plaisir.