$\dfrac{108-x}{92}+\dfrac{107-x}{93}+\dfrac{106-x}{94}+\dfrac{105-x}{95}+4=0$
$↔\bigg(\dfrac{108-x}{92}+1\bigg)+\bigg(\dfrac{107-x}{93}+1\bigg)+\bigg(\dfrac{106-x}{94}+1\bigg)+\bigg(\dfrac{105-x}{95}+1\bigg)=0$
$↔\dfrac{200-x}{92}+\dfrac{200-x}{93}+\dfrac{200-x}{94}+\dfrac{200-x}{95}=0$
$↔(200-x)\bigg(\dfrac{1}{92}+\dfrac{1}{93}+\dfrac{1}{94}+\dfrac{1}{95}\bigg)=0$
$↔200-x=0$ (vì $\dfrac{1}{92}+\dfrac{1}{93}+\dfrac{1}{94}+\dfrac{1}{95}\ne 0$)
$↔x=200$
Vậy pt có tập nghiệm $S=\{200\}$
