How do you find LCM using factor trees?

Answer 1

Example: 30 and 42

30

15,2

5,3,2

42

21,2

7,3,2

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Combine the factors, eliminating duplicates.

2 x 3 x 5 x 7 = 210, the LCM

Answer 2

Example: 30 and 42

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Combine the factors, eliminating duplicates.

2 x 3 x 5 x 7 = 210, the LCM
Example: 30 and 42

Factor them.

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Combine the factors, eliminating duplicates.

2 x 3 x 5 x 7 = 210

Answer 3

Example: 30 and 42

30
15,2
5,3,2

42
21,2
7.3.2

2 x 3 x 5 = 30
2 x 3 x 7 = 42
Combine the factors, eliminating duplicates.
2 x 3 x 5 x 7 = 210, the LCM

Answer 4

30

15,2

5,3,2

42

21,2

7,3,2

Example: 30 and 42

Factor them.

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Combine the factors, eliminating duplicates.

2 x 3 x 5 x 7 = 210, the LCM

Answer 5

The least common factor of any two numbers is one. You don't need a factor tree to tell you that.

Answer 6

Example: 30 and 42

Factor them.

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Combine the factors, eliminating duplicates.

2 x 3 x 5 x 7 = 210, the LCM

Answer 7

LCM- using 14 12 and 10 is 420