exercice maths Equation

1) (2x+1)²-9

= (2x+1+9)(2x+1-9)

= (2x+10)(2x-8)

2) (2x+10)(2x-8)=0       2x+10=0 ou 2x-8=0

                                     2x = -10        2x = 8

                                     x = -5             x = 4

L'équation A=0 a pour solution x= -5 et x= 4