Respuesta :

gmany
[tex]x^2+13x=-42\ \ \ |+42\\\\x^2+13x+42=0\\\\x^2+6x+7x+42=0\\\\x(x+6)+7(x+6)=0\\\\(x+6)(x+7)=0\iff x+6=0\ \vee\ x+7=0\\\\x=-6\ \vee\ x=-7[/tex]

Anaswer: a. x = -6 or x = -7