Aim #102: How do we Factor
using the GCF method?
(Unit 12 - Factoring and Quadratics)
5-12-17
HW #102: GCF Factoring Handout
Do Now: 1) What is the GCF of:
a) 12 and 18
b) x and x
2) Simplify: a) 3(x - 7)
2
2
3
2
c) 24a b and 36a b ?
2
b) 4a(2a - 5a + 9)
What if we know the product and want to work backwards
to find the factors?
Factoring: Breaking down a polynomial into its factors.
Ex #1:
5x + 20 =
(
)
Think: What times the GCF
gives you 5x + 20?
GCF
Step 1: Identify the GCF of the terms and write the GCF outside
parentheses.
Step 2: Divide each term by the GCF to get the other factor in
parentheses.
Step 3: Check with distribution!
Factor by factoring out the greatest common
monomial factor.
5
3
Ex #2:
21y + 14y
Ex #3:
4a b + 2a b - a b
Ex #4:
24yz
Remember:
Factoring is the opposite of
the Distributive Property.
4
3
5
3
2
2
2 4
- 36xy z
To make sure you have correctly
identified the GCF, look at the polynomial
inside the set of parentheses and make
sure there are no more common factors.
Factor by Grouping
Ex #5:
x2 + 4x + 2x + 8
Group the terms
together to form 2 pairs.
Factor the GCF of
each pair.
Factor the GCF of the
entire expression.
Unit 12 Quiz on Friday!