Foil stands for
first
Inner
outer
last
if you had (a+b)(c+d) you would get this by foiling:
Ac+bc+ad+bd
a and c are the first nubers in eac h parenthisese,
b and c are the two numbers in the center
a and d are the two numers on the outside
b and d are last numbers in each parenthisese.
The samne goes for equations for more parenthisese. Hope this helps, and let me know if you need anything else!
first
Inner
outer
last
if you had (a+b)(c+d) you would get this by foiling:
Ac+bc+ad+bd
a and c are the first nubers in eac h parenthisese,
b and c are the two numbers in the center
a and d are the two numers on the outside
b and d are last numbers in each parenthisese.
The samne goes for equations for more parenthisese. Hope this helps, and let me know if you need anything else!
