$\Leftrightarrow \frac{109-x}{91}+1+\frac{107-x}{93}+1+\frac{105-x}{95}+\frac{103-x}{97}+1=0$
$\Leftrightarrow \frac{109-x+91}{91}+\frac{107-x+93}{93}+\frac{105-x+95}{95}+\frac{103-x+97}{97}=0$
$\Leftrightarrow \frac{200-x}{91}+\frac{200-x}{93}+\frac{200-x}{95}+\frac{200-x}{97}=0$
$\Leftrightarrow (200-x)(\frac{1}{91}+\frac{1}{93}+\frac{1}{95}+\frac{1}{97})=0$
$\Leftrightarrow 200-x=0$
$\Leftrightarrow x=200$
