a) 7(6+2x)-(x-7)=0 b) 7(6+2x)(x-7)=0 Merci d'avance.

Bonsoir,

[tex]a)\ 7(6+2x)-(x-7)=0\\42+14x-x+7=0\\13x+49=0\\13x=-49\\\\\boxed{x=-\dfrac{49}{13}}\\\\ \\b) 7(6+2x)(x-7)=0\\(6+2x)(x-7)=0\\6+2x=0\ \ ou\ \ x-7=0\\2x=-6\ \ ou\ \ x=7\\x=-\dfrac{6}{2}\ \ ou\ \ x=7\\\boxed{x=-3\ \ ou\ \ x=7}[/tex]