X/3+x/12=15/x Срочно помогите

$\frac{x}{3} + \frac{x}{12} = \frac{15}{x} \\ \frac{5x}{12} = \frac{15}{x} ; \\ \frac{5x^2-180}{12x}=0 \\ 5x^2=180 \\ x^2=36 \\ x_{1,2}=+6;-6.$

ОДЗ:

$\left \{ {{5x^2-180=0;} \atop {12x \neq 0.}} \right. \\ \left \{ {{5x^2=180;} \atop {x \neq 0.}} \right. \\ \left \{ {{x^2=36;} \atop {x \neq 0.}} \right. \\ \left \{ {{ x_{1,2}=+6;-6 ;} \atop {x \neq 0.}} \right.$