Download Greatest Common Factor ppt

Warm Up May 5
Distribute and simplify
1. 5 x(3x  8 x  4)
2. ( x  4)( 2 x  9)
3. x  7 
4. ( x  3)( x  2 x  6)
2
2
5. ( x  2)
3
2
6. ( x  y)( y  8)
Answers
1.
2.
3.
4.
5.
6.
15x3-40x2+20x
2x2+x-36
x2-14x+49
x3+5x2-18
x3+6x2+12x+8
xy-8x+y2-8y
GCF – what is it??
• It is the term that will divide into all pieces
evenly
– The term has two parts the number and the
variables
• Number – easy, what number will divide into each
part evenly
• Variables, look for the highest exponent each have
– Ex x3 and x2
» Highest they both have is x2, so x2 is the GCF
Factoring 2
Ex 1: 4x2 – 3x
Always factor the GCF first
The GCF for this problem is x, so that will go on
the outside of the ( ).
x(4x – 3)
Example 2 10xy3 + 20y2x3 – 5xy
Remember that both numbers and
variables may be a part of the GCF!
The GCF is 5xy
5xy(2y2+4yx2-1)
Ex 3: -12x – 8x2
Don’t forget that you may also
factor out a negative!
The GCF is -4x
-4x(3+2x)
Ex 4: 5x2 + 7
The GCF is none
Not factorable! When this
happens we write…
“prime” or not factorable
Ex. 5: 5x2(x + 3) – 10x(x + 3)
• Remember the stuff outside ( ) is a factor
and the stuff inside ( ) is a factor.
• (5x2 - 10x)(x + 3)
• Because 5x2 – 10x can still be factored,
we factor out 5x, so…
• 5x(x – 2)(x + 3)
Your Turn
1. 3x – 6
3(x – 2)
2. 5x2y + 15x – 20xy
5x(xy + 3 – 4y)
3. 12x2 – 7y2
Prime
4. 3x(2x – 1) + 2y(2x – 1)
(3x + 2y)(2x – 1)