Multiplying Binomials

By Colleen Turner and Garrett Warnock

What Is A Binomial?
Two terms joined by a plus or minus sign and they are used in algebra
Example
(ax+b)(cx-d)
(3x+7)(7x-3)
The Foil Method
F- first
O- outside
I- inside
L- last
So you multiply the 2 first terms in each set of parentheses, then you multiply the 2 outside terms in each set of parentheses together, then you multiply the 2 inside terms in each set of parentheses together and then you multiply the 2 last terms in each set of parentheses and you add all these together.
3x (7x) + 3x (-7) + 7 (7x) + 7 (-3)
first outside inside last
It's basically like the distributive method.
Big image
Multiplying Binomials
FOIL Song