Tìm BCNN...

- Hướng dẫn giải

a, Ta có: 10 = 2.5; 12 = $2^2$.3

BCNN(10,12) = $2^2$.3.5 = 60

b, Ta có: 24 = $2^3$.3; 56 = $2^3$.7

BCNN(24;56) = $2^3$.3.7 = 168

c, Ta có: 84 = $2^2$.3.7; 108 = $2^2.3^3$

BCNN(84;108) = $2^2.3^3$.7

d, Ta có: 33 = 3.11; 44 = 4.11; 55 = 5.11

BCNN(33;44;55) = 3.4.5.11 = 660

e, Ta có: 8 = $2^3$; 18 = 2.$3^2$; 30 = 2.3.5

BCNN(8,18,30) = $2^3.3^2.5$ = 360

f, Ta có: 40 = $2^3.5$; 28 = $2^2$.7; 140 = $2^2$.5.7

BCNN(40;28;140) = $2^3.5.7$ = 280