Question

2,Tính nhanh

15.37.4 + 120.21 + 21.5.12

dấm . là dấu nhân,mik vt tắt

Answer 1

5.3.37.4+5.24.21+21.5.12

= 5.(3.37.4+24.21+21.12)

= 5.1200

= 6000

Answer 2

15.37.4 + 120.21 + 21.5.12

= (15 .4) . 37 + 60 . 2 . 21 + (12 . 5) . 21

= 60 . 37 + 60 . 42 + 60 . 21

= 60 . (37 + 42 + 21)

= 60 . 100

= 6000

Answer 3

15 . 37 . 4  + 120 . 21 + 21 . 5 . 12

= 15 . 4 . 37 + 21 ( 120 + 5 . 12 )

= 60 . 37 + 21 ( 120 + 60 )

= 2220 + 21 . 180

= 2220 + 3780

= 6000

 

 

Answer 4

15. 37.4 + 120.21+21.5.12 

= 15.4.37 + 6.20.21 + 21.5.2.6

=60.37+ 6.(20.21) + 210 . 6 

= 6 . 10.37 + 6.420 + 210.6

=6.370 +6.420 +210.6

=6.(370+420+210)

=6.1000

=6000

Answer 5

Ta có: \(15\cdot37\cdot4+120\cdot21+21\cdot5\cdot12\)

\(=60\cdot37+60\cdot42+60\cdot21\)

\(=60\left(37+42+21\right)\)

=6000