`#Dark`
`(x+2)/98+(x+4)/96=(x+6)/94+(x+8)/92`
`⇔((x+2)/98+1)+((x+4)/96+1)-((x+6)/94+1)-((x+8)/92+1)=0`
`⇔(x+100)/98+(x+100)/96-(x+100)/94-(x+100)/92=0`
`⇔(x+100)(1/98+1/96+1/94+1/92)=0`
Vì `(1/98+1/96+1/94+1/92) > 0`
`⇔x+100=0`
`⇔x=-100`
Vậy `S={-100}`