On pose D = (5x - 3)² - (5x -3) (8x -1) 1) factoriser D 2) Calculer D pour x = 3/5 aidez moi please ! :((

[tex]D = (5x-3)² - (5x-3)(8x-1) D = (5x-3)(5x-3) - (5x-3)(8x-1) D = (5x-3)(5x-3-(8x-1)) D = (5x-3)(-3x-2) Pour x = \frac{3}{5} D = (5 ( \frac{3}{5}) - 3 (-3( \frac{3}{5})-2) D = 0 [/tex]

D = (5x-3)² - (5x-3)(8x-1)
D = (5x-3)(5x-3) - (5x-3)(8x-1)

Tu remarques l'existence d'un facteur commun : 5x-3

D = (5x-3)[5x-3-(8x-1)]
D = (5x-3)(5x-3-8x+1)
D = (5x-3)(-3x-2)

Pour x = 3/5

D = [5*(3/5)-3][-3*(3/5)-2]
D = (15/5 - 3)(-9/5 - 2)
D = (3-3)(-9/5 - 10/5)
D = (0)(-19/5)
D = 0