Objective 119
Multiplying 2 binomials,
(x + a)(x + b)
©2002 by R. Villar
All Rights Reserved
Multiplying 2 binomials, (x + a)(x + b)
To multiply a binomial by a binomial, you distribute twice…
One way to do this is by using the FOIL method…
FOIL stands for the order you can do the distribution…
First
Outer
Inner
Last
Example: Multiply (x + 4)(x + 1)
The Last means to multiply
the second terms of each binomial...
The First means to multiply
the first term in each binomial...
The Outer means to multiply The Inner means to multiply
the terms on the outside
the terms on the inside
of each binomial...
of each binomial...
x2 + 1x + 4x + 4
Now, combine like terms...
x2 + 5x + 4
Example: Multiply (x – 3)(x + 4)
First
Outer
Inner
Last
x2
+ 4x
– 3x
– 12
Combine like terms...
x2 + x – 12
Example: Multiply (x – 3)(x – 1)
First
x2
Outer
– 1x
Inner
– 3x
Combine like terms...
x2 – 4x + 3
Last
+3