a) Ta có :
1 = 1
8 = 2\(^3\)
=> BCNN ( 1 ; 8 ) = 1 . 8 = 8
b) Ta có :
8 = 2\(^3\)
1 = 1
12 = 2\(^2\). 3
=> BCNN ( 8 ; 1 ; 12 ) = 2\(^3\). 3 . 1 = 24
c ) Ta có :
\(36=2^2.3^2\)
\(72=2^3.3^2\)
=> BCNN ( 36 ; 72 ) = \(2^3.3^2=72\)
d) Ta có :
5 = 5
\(24=2^3.3\)
=> BCNN ( 5 ; 24 ) = \(2^3.5.3=120\)
a/1=1
8=2^3
BCNN(1,8)=1.2^3=8
b/8=2^3
1=1
12=2^2.3
BCNH(8,1,12)=2^3.1.3=24
c/Vì 72 chia hết cho 36 nên BCNN(36,72)=72
d/5=5
24=2^3.3
BCNN(5,24)=5.2^3.3=120
cho mình nha !