College Algebra

COLLEGE ALGEBRA
6.3. Factor by GCF
Do Now:
β€’ Simplify the following statements
2π‘₯ π‘₯ + 4
8 π‘₯ βˆ’ 4 + 2π‘₯ 2
Also… What is the greatest common factor of
9π‘₯ 2 𝑦 and 12π‘₯𝑦 2 𝑧
Homework
β€’ Questions?
β€’ Comments?
β€’ Concerns?
β€’ Confusions?
β€’ ASK ASK ASK!
Today:
β€’ We have been so focused on distributing things IN in
order to simplify expressions…. What happens if we want
to distribute OUT instead?
Example One:
β€’ Factor Completely
16𝑛 βˆ’ 8
So…. Always ask yourself, what can we take out? What do
all the terms have in common?
Example Two:
β€’ Factor Completely
32 βˆ’ 56𝑛
You Try!
β€’ Factor Completely
3π‘₯ βˆ’ 27
42 βˆ’ 9π‘Ž
Example Three:
β€’ What happens when we add in some variables? Factor
Completely
6π‘₯ 2 𝑦 3 + 2π‘₯ 5
Example Four:
β€’ Factor Completely
8π‘₯ 2 𝑦 4 βˆ’ 16π‘₯ 5 𝑦 4 + 4π‘₯ 2 𝑦 3
Example Five:
Factor Completely
3π‘Ž4 𝑏 8 𝑐12 βˆ’ 9π‘Ž2 𝑏 5 𝑐 2 + 12π‘Ž7 𝑏 3 𝑐
Realize:
Always start with the numbers. Then go to one variable,
and then go to another variable…. Don’t try to do it all at
once! You will get overwhelmed and confused very quickly!
Bottom Line: Go in a logical order!
You Try!
β€’ Factor Completely
3π‘Ž2 𝑏 2 βˆ’ 6π‘Ž5 𝑏 4 + 9π‘Ž3 𝑏
15π‘₯ 2 𝑦 + 12π‘₯𝑦 βˆ’ 9π‘₯ 3 𝑦 5
*Realize:
β€’ Sometimes we may have some pieces that work, but not
others….. You need to find the common pieces for ALL
terms, not just some!
Example Six:
β€’ Factor Completely
βˆ’48 + 24π‘Ÿ + 56π‘Ÿ 2 + 48π‘Ÿ 3
Example Seven:
β€’ Factor Completely
βˆ’25π‘₯ 2 𝑦 3 + 25π‘₯ 4 𝑦 + 10π‘₯ 4 + 15π‘₯ 3
Example Eight:
β€’ Factor Completely
18π‘₯ 4 βˆ’ π‘₯ 2 + 6π‘₯ 8 𝑦
You Try!
β€’ Factor Completely
14π‘˜ 3 + 21π‘˜ + 49
12π‘š2 𝑛7 βˆ’ 9π‘šπ‘›2 βˆ’ 12π‘šπ‘›3 + 15𝑛2
3π‘Žπ‘ 3 βˆ’ 6π‘Ž3 𝑏 4 + ab2 βˆ’ 9a2 b3
Example Nine:
β€’ Slightly Trickier– Factor Completely
66π‘Ž4 𝑏 8 𝑐 βˆ’ 𝑑 + 11π‘Ž3 𝑏𝑐 + 𝑏𝑑
Example Ten:
β€’ Factor Completely
6π‘₯ 3 π‘₯𝑦 2 + 𝑦 βˆ’ 3π‘₯ π‘₯ 3 𝑦 3 βˆ’ π‘₯ 2 𝑦
Example Eleven:
β€’ Factor Completely
10π‘₯ 2 𝑦 π‘Ž2 𝑏 3 βˆ’ π‘Ž5 𝑏 2 + 30π‘₯ 3 𝑦 3 (π‘Ž5 𝑏 + 𝑏 5 π‘Ž)
You Try!
β€’ Factor Completely
βˆ’3π‘₯ 3 𝑦 8π‘₯𝑦 2 𝑧 βˆ’ 1 + 2π‘₯ 3π‘₯𝑦 3 𝑧 βˆ’ 9π‘₯ 2 𝑦 5
10𝑦 5𝑦 2 + 2𝑦 βˆ’ 3𝑦 3 βˆ’ 10𝑦 4
3π‘₯ 3 2 βˆ’ 5π‘₯ 2 + 2(9π‘₯ 3 βˆ’ 3π‘₯ 5 )
Do Now:
β€’ Factor Completely
25π‘₯𝑦𝑧 2 + 10𝑦 2 𝑧 + 5𝑦𝑧
40𝑧 3 𝑦 + 32𝑧π‘₯ 3 + 40𝑧π‘₯𝑦 + 48𝑧π‘₯
28π‘₯ 6 𝑦 2 + 4π‘₯ 3 𝑦 2 βˆ’ 24π‘₯ 3 𝑦 4 + 24π‘₯ 3 𝑦 3
βˆ’24π‘Ž2 𝑏 5 βˆ’ 20π‘Žπ‘ 3 βˆ’ 16π‘Ž2 + 16π‘Žπ‘
Example Twelve:
β€’ Even Trickier: Factor Completely
3𝑝 + 𝑝2 2𝑝2 βˆ’ 1 + 2𝑝4 𝑝2 + 4𝑝
Example Thirteen:
β€’ Factor Completely
π‘₯ 2 βˆ’ 5π‘₯ 2𝑦 3 + 𝑦 2 βˆ’ π‘₯𝑦 2
You Try!
β€’ Factor Completely
8π‘₯ π‘₯𝑦 3 + 𝑦 2 + 3π‘₯𝑦 βˆ’ 𝑦 2π‘₯ 2 + π‘₯𝑦
Example Fourteen:
β€’ Find two numbers….
β€’ A) Whose sum is 8 and whose product is 12
β€’ B) Whose sum is 15 and whose product is 36
β€’ C) Whose sum is -8 and whose product is 16
β€’ D) Whose sum is -17 and whose product is 30
Example Fifteen:
β€’ Find two numbers….
β€’ A) Whose sum is 2 and whose product is -63
β€’ B) Whose sum is -4 and whose product is -32
β€’ C) Whose sum is -7 and whose product is -60
You Try!
β€’ Find two numbers…
β€’ A) Whose sum is 17 and whose product is 70
β€’ B) Whose sum is 5 and whose product is -24
β€’ C) Whose sum is -2 and whose product is -24
β€’ D) Whose sum is -30 and whose product is 81
Practice Problems
β€’ Try some on your own/in your table groups
β€’ As always don’t hesitate to ask me questions if you are
confused OR talk to a tablemate– they are your greatest
resource!