\[ \frac{x}{1000} + \frac{x+2}{998} + \frac{x+4}{996} + \frac{x+6}{994} = \frac{x+1}{999} + \frac{x+3}{997} + \frac{x+5}{995} + \frac{x+7}{993} \]

GIẢI PHƯƠNG TRÌNH
\[
\frac{x}{1000} + \frac{x+2}{998} + \frac{x+4}{996} + \frac{x+6}{994} = \frac{x+1}{999} + \frac{x+3}{997} + \frac{x+5}{995} + \frac{x+7}{993}
\]