6.4 and 6.5 Factoring Trinomials
“Using Bottom’s Up Method”
The X factor
• To begin factoring trinomials draw a BIG X
North
East
West
South
• East and West multiplied together = North
• East and West added together =South
The X Factor
• Do the worksheet
The X Factor: How to put a trinomial
in the X
• Make sure the polynomial is in descending order: ax²
+bx +c
• If ax² is – factor out a -1 before you begin
• If there is a common factor, factor it out before you
begin to put it in the X
• Multiply a and c to get the North term
• Write b in the South
• Find what two numbers add to get the south and
multiply to get the north. Those two numbers are your
east and west
X Factor: 4 Options
+
+
- - Larger #
+
+
Smaller #
-
Larger #
-
+
+
+
+
-
Smaller #
The X Factor: With Trinomials
• Worksheet
Bottom’s Up
1. Factor out a common factor
2. Draw your X and do the X Factor
3. Make East an d West your binomials
(x + west) (x + East)
4. Divide West and East by the # in front of x²
5. Simplify (reduce fraction)
6. Bring the bottom number up in front of x
See Examples