\(\frac{x+5}{x^2-5x}-\frac{x+25}{2x^2-50}=\frac{x-5}{2x^2+10x}\) (α)
ĐKXĐ : \(x\ne0;x\ne\pm5\)
Với đk trên, ta có :
(α) ⇔ \(\frac{2\left(x+5\right)^2}{2x\left(x^2-25\right)}-\frac{x^2+25x}{2x\left(x^2-25\right)}=\frac{\left(x-5\right)^2}{2x\left(x^2-25\right)}\)
⇔ \(2\left(x^2+10x+25\right)-x^2-25x=x^2-10x+25\)
⇔ \(2x^2+20x+50-x^2-25x=x^2-10x+25\)
⇔ \(2x^2-x^2-x^2+20x-25x+10x=25-50\)
⇔ \(5x=-25\)
⇔ \(x=-5\) (loại)
Vậy : \(S=\varnothing\)