\(\dfrac{x+1}{x-2}-\dfrac{5}{x+2}=\dfrac{12}{x^{12}-4}+1\left(ĐKXĐ:x\ne\pm2\right)\)
\(\Leftrightarrow\dfrac{\left(x+1\right)\left(x+2\right)-5\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{12+\left(x-2\right)\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}\)
\(\Rightarrow\left(x+1\right)\left(x+2\right)-5\left(x-2\right)=12+\left(x^2-4\right)\)
\(\Leftrightarrow x^2+2x+x+2-5x+10=12+x^2-4\)
\(\Leftrightarrow x^2-2x+12=x^2+8\)
\(\Leftrightarrow x^2-x^2-2x=8-12\)
\(\Leftrightarrow-2x=-4\)
\(\Leftrightarrow x=2\) (loại)
Vậy S = ∅