Download 11-12-13 GCF.notebook

11­12­13 GCF.notebook
November 12, 2013
11-12-13
Aim: SWBAT find the GCF of expressions.
Do Now: What is the Greatest Common Factor of
15 and 30?
8 and 20?
x3 and x?
HW: Finish WS (GCF side)
Quiz tomorrow (simplifying)
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11­12­13 GCF.notebook
November 12, 2013
Pg. 90 - 91 # 16 - 30
Here are the answers in their best form.
16.
9x - 27
22.
4r + 2s
17.
8x - 40
23.
16w + 12z
18.
- 12y - 108
24.
5a + 6b
19.
19w + 95
25.
5x + 3y - 3
20.
-34z + 884
26.
-3x - 9y
21.
2x + 6
27.
4r + s
28.
The student put together unlike terms. The
Don't write the 1
answer should be 2x - 5y.
29.
11z
30.
2x + 2
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11­12­13 GCF.notebook
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Factor (noun): A number or expression that is multiplied by
another to yield a product.
Greatest Common Factor (GCF): the greatest number or
expression that is a factor of two or more numbers or
expressions.
Old Ways...
Find the GCF of 12 and 20.
12 4 = 3
The GCF is 4 because it is the largest number you
can divide out 12 and 20.
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20 4
Common Factors vs. Greatest Common Factor
÷
÷
12 and 20
12: 1, 2, 3, 4, 6, 12
20: 1, 2, 4, 5, 10, 20
There are 3 common factors, but 4
is the largest so it is the GCF.
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11­12­13 GCF.notebook
November 12, 2013
What are all the factors and what is the GCF?
1) 24 =_____________________
2) 50 =______________________
6 =______________________
30 =______________________
The GCF of 24 and 6 is _______
The GCF of 50 and 30 is _______
Find the GCF of 36 and 60 listing out all the factors.
Find the GCF of 9, 36 and 63 listing out all the factors.
36:___________________________________
9:____________________________________
60:___________________________________
36:___________________________________
GCF:_______________
63:___________________________________
GCF:_______________
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11­12­13 GCF.notebook
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Monomial: A polynomial with one term; it's a number, a
variable, or the product of a number and one or more
variables.
Factor the monomial.
1. 12x2y
2 2 3 x x y
2. 3mn
3 m n
4. 14x3y2
2 7 x x x y y
5. 87c3d7
3 29 c c c d d d d d d d
3. 18t2
2 3 3 t t
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11­12­13 GCF.notebook
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New Ways...
Find the GCF of 12 and 20.
12
12
12
This works because 12 is a factor of itself.
20
This does not work because 12 is not a factor of 20.
Therefore, 12 is not the GCF.
6
6
12
This works because 6 is a factor of 12.
20
This does not work because 6 is not a factor of 20.
Therefore, 6 is not the GCF.
4
4
12
This works because 4 is a factor of 12.
20
This works because 4 is a factor of 20.
Therefore, 4 is the GCF.
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November 12, 2013
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11­12­13 GCF.notebook
November 12, 2013
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