a, 202203=(101.2)203
=101203.2203
=101202.2202.202
b, 203202=(101,5.2)202
=101,5202.2202
còn lại dễ
b, 199010+19909=19909.1990+19909=19909.(1990+1)=19909.1991
199120=199119.1991
=>199010+19909<199120
c, 111979<111980=(113)660=1331660
371320=(372)660=1369660
=>111979<371320