a) 29.64 - 29.24 + 40.81 =
29.(64 - 24) + 40.81 =
29.40 + 40.81 =
40.(29 + 81) =
40.110 = 4400
b) 14.35.5 + 10.25.7 + 20.70 =
70.35 + 70.25 + 20.70 =
70.(35 + 25 + 20) =
70.80 = 5600
c) 48.25 + 48.35 + 48.12 + 52.72 =
48.(25 + 35 + 12) + 52.72 =
48.72 + 52.72 =
72. (48 + 52) =
72.100 = 7200
d) 15.37.4 + 120.21 + 21.5.12 =
60.37 + 60.2.21 + 21.60 =
60.(37 + 42 + 21) =
60.100 = 6000