a . 297+150:(493-47.10+7 b, 728:(73.3,54+0,17.25+3,54.27+0,23.25
=297+150:(493-470+7) =728:[(73.3,54+3,54.27)+(0,23.25+0,17.25)]
=297+150:30 =728:[3,54.(73+27)+25.(0,17+0,23)]
=297+5 =728:(3,54.100+25.0,4)
=302 =728:(354+10)
=728:364
=2
'.' là dấu phẩy