35 25 33 23 89 56 75 52 68 33 37 12 https //sites google com/view/tailieuhoidvier/d%E1%BB%8Bch v%E1%BB%A5 lau d%E1%BB%8Dn nh%C3%A0 t%E1%BA%A1i thanh h%C3%B3a s%E1%BA%A7m s%C6%A1n?authuser=0 60 – 30 =[.]
37 - 12 35 68 - 33 75 - 52 89 - 56 25 33 23 70 - 10 = …… 60 – 30 = …… 90 - 80 = …… 55 - = …… 22 - = …… 46 - = …… A 30 cm B C ? cm Thì thầm