# 9-3 Factoring Trinomials x2 + bx + c ```FACTORING TRINOMIALS
2
AX + BX + C; A = 1
Ex
A) x2 + 11x + 24
backwards in a way – what
numbers can be multiplied to give you
24 that when you add you get 11? 8
and 3
If
the second sign is positive – both
signs are the same. They will be what
the first sign is.

( x + 3) (x + 8)
X2 – 3X + 2

(x - ) (x -
)
What number can you multiply to
get 2 that add to give you 3?



2 and 1
(x - 2 ) (x - 1 )
X2 – 12X + 36

2X2 + 10X + 8
Ex
A) x2 + 5x - 24
Read backwards in a way – what
numbers can be multiplied to give
you 24 that when you subtract you
get 5? 8 and 3
signs are different and the largest #
goes with the first sign.
( x - 3) (x + 8)
X2 – 5X – 14
X2 – 3X – 10
3X2 + 6X – 9
2x2
– 18x – 20
x 2
– 7x + 12
X2
– 6x - 27
x 2
+ 20x + 51
54
– 15x + x2
72 – 17x
TRY THESE!
+ x2
2x2
– 18x – 20
= 2(x + 1)(x - 10)
x2
– 7x + 12
= (x – 3)(x – 4)
x2
– 6x – 27
= (x – 9)(x + 3)
x2
+ 20x + 51 = (x + 17)(x + 3)
54
– 15x + x2 = (x – 6)(x – 9)
72
– 17x + x2 = (x – 8)(x – 9)
TRY THESE!
```