解:原式??$=\frac {2(x-3)}{x2-9}+\frac {2(x+3)}{x2-9}+\frac {2x+18}{x2-9}$??
??$ =\frac {2x-6+2x+6+2x+18}{x2-9}$??
??$ =\frac {6}{x-3}$??
因為分式的值為整數(shù)
所以??$x-3=±1,$????$±2,$????$±3,$????$±6$??
因為分式有意義
所以??$x≠3$??且??$x≠-3$??
所以??$x=0,$????$1,$????$2,$????$4,$????$5,$????$6,$????$9$??
和為??$27$??