Réponses

2014-03-06T15:10:31+01:00


Tu fais Pythagore !

(x+3)²=x²+6²

=> x² + 6x + 9 = x² + 36  (On barre les x² car x²-x² = 0)

=> 6x + 9 = 36

=> 6x = 36-9

=> 6 x = 27

=> x = 27/6

=> x = 4.5 cm