a与2b互为倒数,2ab=1
-c与d/2（二分之d）互为相反数,-c+d/2=0,c=d/2
|x|=3,x=±3
2ab-2c+d+x/3
=1-2*d/2+d+x/3
=1-d+d+x/3
=1+x/3
=1±3/3
=0或-2