Luttrell 2012
116
Name: ______________________
Date: _____
8c – Factoring
Factoring when
a
= 1,
c
< 0:
A quadratic in the form of
x
2
±
bx
-
c
can be factored into (
x-d
)(
x+e
) whenever the
c
term
divisors differ b
y
the middle term
b
. The larger factor will have the same sign as
b
; the other
factor will have the opposite sign.
E
x
ample A:
x
2
+ 5
x
- 6
Y
ou probabl
y
won’t have more than one line of
( )( )
work on
y
our paper. But these are the steps to fill
(
x
)(
x
)
in the parentheses. Note (
x
6)(
x
1) was chosen
Choices: (
x
1)(
x
6) Or (
x
2)(
x
3) because 6 - 1 = 5. The signs are last to be done.
(
x
+ 6)(
x
- 1)
E
x
ample B:
x
2
-
x
- 30
( )( )
Fill in the missing numbers!
(
x
)(
x
)
Choices: (
x
±
)(
x
3) or (
x
1)(
x
30) or (
x
2)(
x
18) or (
x
5)(
x
±
)
(
x
- 6)(
x
+ 5)
Factor. Check work.
1.
x
2
+
x
- 6
2.
x
2
+ 3
x
- 10
3.
x
2
- 8
x
- 20
4.
x
2
+ 4
x
- 12
5.
x
2
- 6
x
- 16
6.
x
2
-
x
- 12
7.
x
2
- 16
8.
x
2
+ 3
x
- 18
9.
x
2
- 7
x
- 18
10.
x
2
- 36
11.
x
2
+ 8
x
- 9
12.
x
2
- 9
x
- 36
