a) 13 . 57 + 43.13 = 13.(57 + 43)
= 13 . 100 = 1300
b) 39 . 28 + 39 . 72 = 39 . (28 + 72)
= 39 . 100 = 3900
c) 345 . 69 - 245 . 67 = (345 - 245) . 67
= 100 . 67 = 6700
d) 123 . 34 + 123 . 26 + 123. 40 = 123 . (34 + 26 + 40)
= 123 . 100 = 12300
e) 974 . 34 + 974 . 96 - 974 . 30 = 974 . (34 + 96 - 30)
= 974 . 100 = 97400
f) 37 . 148 - 37 . 53 + 37 . 5 = 37 . (148 - 53 + 5)
= 37 . 100 = 3700
9) 47 . 173 + 47 + 66.47 = 47 . (173 + 1 + 66)
= 47 . 240 = 11280
h, i ) tự làm