8.代入x=0,得：a/-2=b,设a=1,则b=-1/2，分式方程是1/(x-2)=-1/29.依题意得:2⊕（2x-1)=1/(2x-1）-1/2=[2-(2x-1)]/2（2x-1）=(3-2x)/(4x-2)=1解得：x=5/6
