Bonsoir j'aurais besoin d'aide pour mon dm de mathématiques. Consigne : factoriser chaque expressions A=(x+1)*-9 B=(4x+3)*-1 C=4-(2x+1)* D=(5x-3)*-x*. (

bonsoir

a = (x+1)² -3² = (x+1-3)(x+1+3) =(x-2)(x+4)

b =(4x+3)² -1² =(4x+3-1)(4x+3+1) =(4x-2)(4x+4)=2(2x-1)4(x+1) =8(2x-1)(x+1)

c =2²-(2x+1)² = (2-2x-1)(2+2x+1) =(-2x+1)(2x+3)

d =(5x-3-x)(5x-3+x) =(4x-3)(6x-3) =3(4x-3)(2x-1)

Bonsoir , 
A = (x+1)² - 9
A = (x+1)² - 3²
A = [ (x+1) + 3 ] [ (x+1) - 3 ]
A = (x + 4 ) ( x - 2 ) 
B = (4x+3)² - 1 
B = (4x+3)² - 1²
B = [ (4x+3) - 1 ] [ (4x+3) + 1 ]
B = ( 4x + 2 ) ( 4x + 4 ) 
C = 4 - (2x+1)²
C = 2² - (2x+1)²
C = [ 2 - (2x+1) ] [ 2 +(2x+1) ]
C = [ 2 - 2x - 1 ] [ 3 + 2x ]
C = (1 - 2x ) (3 + 2x )
D = (5x-3)² - x²
D = [ (5x-3) + x ] [ (5x-3) - x ]
D = (6x-3) (4x-3 )