6 1/10*2,391-0,109*1 5/6-1 5/6*2,391+0,109*6 1/10=
=2,391*(6 1/10-1 5/6)-0,109*(1 5/6-6 1/10)=
2,391*(6 3/30-1 25/30)-0,109*(1 25/30-6 3/30)=
=2,391*(183/30-55/30)-0,109*(55/30-183/30)=
=2,391*128/30-0,109*(-128/30)=2,391*128/30+0,109*128/30=
=128/30*(2,391+0,109)=128/30*2,5=128/30*25/10=64/6=10 4/6= 10 2/3