Respuesta :

[tex]{\frac{x}{x-6}+\frac{3}{x+7}=\frac{x(x+7)+3(x-6)}{(x-6)(x+7)}=\frac{x^2+7x+3x-18}{(x-6)(x+7)}=\frac{x^2+10x-18}{(x-6)(x+7)}}[/tex]

domain

[tex]x\ne 6 \ , \ x\ne -7 \\\\ D: \ x \in \mathbb R - \{-7,6\}[/tex]