How do use A factor tree to find a gcf?

Answer 1

Factor trees are ways of notating the prime factorizations of composite numbers. Once you have the prime factorization, you can find the GCF.

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

Select the common factors.

2 x 3 = 6, the GCF

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Here is another example. Since the greatest common factor of two or more numbers is the product of all of the prime factors that they have in common, first we break the numbers down to their prime factors. Consider, for example, 5940 and 5544:

5940 = 22 x 33 x 5 x 11

5544 = 23 x 32 x 7 x 11

All of the prime factors that the numbers have in common are

22 x 32 x 11

which equals 396, so 396 is the greatest common factor of 5940 and 5544.

Answer 2

Example: 30 and 42

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Select the common factors.

2 x 3 = 6, the GCF

Answer 3

All you do is a factor tree and use the prime numbers that nopth numbers have and multiply..... 94 x 76.......

Kimi03

Answer 4

Example: 30 and 42

2 x 3 x 5 = 30

2 x 3 x 7 = 42

2 x 3 = 6, the GCF

Answer 5

Example: 30 and 42

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Select the common factors.

2 x 3 = 6, the GCF

Answer 6

It doesn't matter what you use; you need more than one term to find a GCF.

Answer 7

Example: 30 and 42

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Select the common factors.

2 x 3 = 6, the GCF

Answer 8

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

Answer 9

Example: 30 and 42

Factor them.

2 x 3 x 5 = 30

2 x 3 x 7 = 42

Select the common factors.

2 x 3 = 6, the GCF