bonjour J'ai besoin d'aide!!!​

Bonsoir

1)(3x+1)²-(3x+1)(2x-1)

9x²+6x+1-(6x²-3x+2x-1)

9x²+6x+1-6x²+3x-2x+1

3x²+7x+2

2)(3x+1)²-(3x+1)(2x-1)

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

(3x+1)(x+2)

3a)(3x+1)(x+2)=0

3x+1=0  ou x+2=0

x=-1/3 ou x=-2

b)x=2/3

3x²+7x+2

=3*(2/3)²+7*2/3+2

=3*4/9+7*2/3+2

=4/3+14/3+2

=4/3+20/3

=8

*=multiplier