Bonjour,

Il arrive de changer de signes ou d'ouvrir les parenthèses, suivre bien la consigne

Exercice 3:

Factoriser:

A(t)= (3t+1-4t+1)(3t+1+4t-1)

A(t)= (-t +2)(7t)= <=> 7t (-t+2)

B(t)= [ 3(t+1)-2(2t+3) ] [3(t+1)+2(2t+3) ]  

B(t)= (3t+3-4t-6)(3t+3+4t+6)

B= (-t-3)(7t+9)

B -(t+3)(7t+9)

C(t)= (t+1)²+(t+1)(3t-5)

C(t)= (t+1)(t+1+3t-5)

C(t)= (t+1)(4t-4)

C(t)= 4(t+1)(t-1)

D(t)= (2t+1)²+(2t-1)(2t+1)

D(t)= (2t+1)(2t+1+2t-1)

D(t)= (2t+1)(4t)

D(t)= 4t(2t+1)

Exercice 4:

A(x)= (5x-1)²+2(5x-1)

A(x)= (5x-1)(5x-1+2)

A(x)= (5x-1)(5x+1)

B(x)= 3(3x+2)-(3x+2)²

B(x)= (3x+2)(3-3x-2)

B(x)= (3x+2)(-3x+1)

B= -(3x+2)(3x-1)

C(x)= (2x+5)(2-x)-(2-x)

C(x)= (2-x)(2x+5-1)

C(x)= (2-x)(2x+4)

C(x)= -2(-2+x)(x+2)