9=32
81=34
ƯCLN(9,81)=32=9
18=2.32
42=2.3.7
ƯCLN(18,42)=2.3=6
28=22.7
40=23.5
140=22.5.7
câu cuối là BCLN hay BCNN hay ƯCLN vậy hả bạn?
ƯCLN ( 9 , 81 ) = 9
ƯCLN ( 18 , 42 ) = 2 . 3 = 6
BCLN ( 28 , 40 , 140 ) = 2 mũ 3 x 5 x 7 = 280
9=32
81=34
=>ƯCLN(9,81)=32=9
18=2.32
42=2.3.7
=>ƯCLN(18,42)=2.3=6
28=22.7
40=23.5
140=22.5.7
=>BCNN(28,40,140)=23.5.7=280