Question

Use the method of dividing byprime factor to find the least common multiple of 14,21,40

Answer 1

Divide all numbers by prime factors

`\begin{gathered} \mathrm{lcm}(14,21,40) \\ \end{gathered}`

14 21 40 | 2

7 21 20 | 2

7 21 10 | 2

7 21 5 | 5

7 21 1 | 7

1 3 | 3

1 |

Now, multiply all this numbers to find the least common multiple

`\mathrm{lcm}(14,21,40)=2\cdot2\cdot2\cdot5\cdot7\cdot3=840`

The least common multiple is 840