Đáp án+Giải thích các bước giải:

a.

Ta có:

$\text{54 = 2 ⋅ $3^{3}$}$

$\text{60 = $2^{2}$ ⋅ 3 ⋅ 5 }$

=> $\text{ƯCLN (54; 60) = 2 ⋅ 3 = 6}$

=> $\text{BCNN (54; 60) = $2^{2}$ ⋅ $3^{3}$ ⋅ 5 = 540}$

b.

Ta có:

$\text{35 = 5 ⋅ 7}$

$\text{42 = 2 ⋅ 3 ⋅ 7}$

$\text{162 = 2 ⋅ $3^{4}$}$

=> $\text{ƯCLN (35; 42; 162) = 1}$ 

=> $\text{BCNN (35; 42; 1620) = 2 ⋅ $3^{4}$ ⋅ 5 ⋅ 7 = 5670}$