Réponses

2014-09-21T13:34:07+02:00

Bonjour


(x+2)(ax² + bx + c)

ax^3 + bx² + cx + 2ax² + 2bx + 2c

ax^3 + bx² + 2ax² + 2bx + cx + 2c

ax^3 + (b + 2a)x² + (2b + c)x + c


a = 1

b + 2a = 0      b + (2  x 1) = 0    b + 2 = 0   b = -2

2b + c = 0        (2    x   -2) + c = 0     -4 + c = 0     c = 4


donc,

a = 1

b= -2

c = 4

 on a: (x+2)(x² - 2x + 4)