1. Lesson Presentation/Cornell Notes
Factors and Greatest
Common Factors
7-1
Warm Up
Lesson Presentation/Cornell Notes
Lesson Quiz
Holt McDougal Algebra 1
Holt Algebra 1

2. Warm Up 21
2. 28.
List the factors of:

3. Essential Questions How do you write the prime
factorization of numbers?
How do you find the GCF of
monomials?

4. Vocabulary
prime factorization
greatest common factor

5. Factorizations of 12
1 12 
2 6
3 4

6. Example
Find the GCF of each pair of numbers:
12 and 16
Method 1 List the factors.
List all the factors.
factors of 12: 1, 2, 3, 4, 6, 12
Circle the GCF.
factors of 16: 1, 2, 4, 8, 16
The GCF of 12 and 16 is 4.

7. Example: Finding the GCF of Monomials
8x2 and 7y3
8x2 = 2  2  2  x  x
7y3 = 7  y  y  y
Nothing common except 1!
The GCF 8x2 and 7y3 is 1.

8. I do….
Find the GCF of each pair of monomials.
18g2 and 27g3
18g2 = 2  3  3  g  g
27g3 =  3  3  g  g  g
3  3  g  g
Find the product of the common factors.
The GCF of 18g2 and 27g3 is 9g2.

9. Find the GCF of each pair of monomials.
We do….
Find the GCF of each pair of monomials.
16a6 and 9b
16a6 = 2  2  2  2  a  a  a  a  a  a
9b =  3  b
The GCF of 16a6 and 9b is 1.
There are no common factors other than 1.

10. You do….
Find the GCF of each pair of monomials.
8x and 7v2
8x = 2  2  2  x
7v2 =  v  v
There are no common factors other than 1.
The GCF of 8x and 7v2 is 1.

11. Write the prime factorization of each number.
1. 50
Find the GCF of each pair of numbers.
2. 18 and 75
Find the GCF of each pair of monomials.
3. 12x and 28x3
Lesson Quiz