bjr
Factoriser les expressions suivantes.
a) (2x + 1)(x+4) + (2x + 1)(5 - 4x)
= (2x+1) [(x+4) + (5-4x)]
= (2x+1) (x+4+5-4x)
= (2x+1) (-3x+9)
= 3 (2x+1) (-x+3)
b)x² + 4x+4
=(x+2)²
c) 36-x² = 6² - x² = (6+x) (6-x)
et
d) x² + 4x = x * x + x * 4 = x (x+4)