[1/(8又4/9+2又1/11-2又4/9)+1]*0.89
=[1/(8又4/9-2又4/9+2又1/11)+1]*0.89
=[1/(6+2又1/11)+1]*0.89
=[1/89/11+1]*0.89
=11/89*0.89+1*0.89
=0.11+0.89
=1