СРОЧНО 2.1 ДАЮ 15 БАЛЛОВ !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

$\frac{12-x}{x^{2}+6x }+\frac{3}{x^{2}-6x }=\frac{6}{x^{2}-36 }\\\\\frac{12-x}{x(x+6)}+\frac{3}{x(x-6)}-\frac{6}{(x+6)(x-6)}=0\\\\\frac{12x-72-x^{2}+6x+3x+18-6x }{x(x+6)(x-6)}=0\\\\\frac{-x^{2}+15x-54 }{x(x+6)(x-6)} =0\\\\\frac{x^{2}-15x+54 }{x(x+6)(x-6)}=0\\\\\left \{ {{x^{2}-15x+54=0 } \atop {x\neq0;x\neq-6;x\neq6}} \right. \\\\x_{1} =9\\\\x_{2}=6$

x = 6 - посторонний корень

Ответ : 9