1. Warm Up
What are the possible lengths and widths that could result in a rectangle that has an area of 24 units2?
Hint: There are eight
24 units2
6 x 4
12 x 2
Width?
4 x 6
2 x 12
1 x 24
Length?
3 x 8
24 x 1
8 x 3

2. Warm up
Vocabulary and notes for section 7-1
Assignment 7-1

3. Introducing… chapter 7 Vocabulary!
A number > 1 whose only
factors are 1 and itself
2, 3, 5, 7, 11, 31
7.1
Has more than 2 factors
(NOT primes)
7.1
4, 100, 2x2 20
4·5
2·2·5
A whole number written
as a product of primes
7.1
25x2 + 5x
The biggest amount that
can be divided out of all parts
7.1
GCF = 5x

4. Lesson 7.1
Learning Target:
I can find GCF’s (greatest common factors)

5. Example 1: Find GCF’s (greatest common factors)
Find the prime factors of each
composite term
and
- Make a factor tree
- Circle the primes
2. List the prime factorizations
12 = 2 · 2 · 3
28 = 2 · 2 · 7
3. Circle the common factors
GCF = 2 · 2 = 4

6. Example 2: Find GCF’s (greatest common factors)
and
27 and
7 and
hint:
Are you ready?
Are you ready?
GCF = 3
50 = 2 · 5 · 5
45 = 3 · 3 · 5
GCF = 1
GCF = 5

7. Example 3: Find GCF’s (greatest common factors)
27a2b and ab2c
15r r2s r2s
15r = r r r
35r2s2 = r r s s
70r2s = r r s
27a2b = 3 · 3 · 3 a a b
-15ab2c = -1 · 3 · 5 a b b c
The answer appears next. Are you ready?
GCF = 3ab
GCF = 5r2

8. Quicker way…don’t need to write….
Find the GCF of .
Factor each number.
Circle the common prime factors.
Answer: The GCF of and is .
Example 1-5a

9. Find the GCF of each set of monomials. a. 15 and 35
Check yourself….Did you master today’s objective?
Find the GCF of each set of monomials.
a. 15 and 35 b.
and
Answer: 5
Answer:
Example 1-5b

10. Assignment 7-1: