0．999＊0．6＋0．111＊3．6=0.999*0.6+0.111*6*0.6=0.333*3*0.6+0.222*3*0.6=(0.333+0.222)*3.*0.6=0.555*1.8=0.999 0．52＊25／2．6=0.52*25*(1/2.6)=0.52*(1/2.6)*25=0.2*25=517．5＊7／2．5 =35/2*7÷（5/2）=35...