5.3.37.4+5.24.21+21.5.12
= 5.(3.37.4+24.21+21.12)
= 5.1200
= 6000
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
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
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
Ta có: \(15\cdot37\cdot4+120\cdot21+21\cdot5\cdot12\)
\(=60\cdot37+60\cdot42+60\cdot21\)
\(=60\left(37+42+21\right)\)
=6000
