bonsoir
( x + 3 ) ( x + 2) + x² + 4 x + 4 = 0
( x + 3 ) ( x + 2 ) + ( x + 2 )² = 0
( x + 2 ) ( x + 3 + x + 2 ) = 0
( x + 2 ) ( 2 x + 5 ) = 0
1 des facteurs est nul
donc x = - 2 ou - 5/2
x² + 6 x + 9 = x² - 4 x
x² - x² + 6 x + 4 x = - 9
10 x = - 9
x = - 9/10
( 2 x - 1 ) ( x + 5 ) = 4 x² - 1
( 2 x - 1 ) ( x + 5 ) - ( 2 x - 1 ) ( 2 x + 1 ) = 0
( 2 x - 1 ) ( x + 5 - 2 x - 1 ) = 0
( 2 x - 1 ) ( - x + 4 ) = 0
x = 1/2 ou 4
