Ta có: 60 = 22 . 3 . 5
280 = 23 . 5 . 7
=> BCNN (60,280) = 23 . 3 . 5 . 7 = 840
Ta có : 60 = 22 x 3 x 5
280 = 23 x 5 x 7
-> BCNN ( 60, 280) = 23 x 3 x 5 x 7 = 840
Ta có : 60 = 22 . 3 . 5
280 = 23 . 5 . 7
=> BCNN ( 60 , 280 ) = 23 . 3 . 5 . 7 = 840