Question

tinh nhanh   15.37.4+120.21+21.5.12

Answer 1

=(15.4).37+60.2.21+(12.5).21

=60.37+60.42+60.21

=60.(37+42+21)

=60.100

=6000

Answer 2

= 15 . 37 . 4 + 15 . 8 + 3 . 7 + 3 .7 . 5 . 12

= 15 . 37 . 4 + 15 . 8 + 3 . 7 + 15 . 7 . 12

= 15 . (37 . 4 + 8 + 3 . 7 + 7 . 12)

= 15 . 261

= 3915

  tick đúng cho tớ nhé !