What is FOIL?

1 Answer
Mar 20, 2018

It's a rule.

Explanation:

It's a rule commonly used in factoring, meaning to start by multiplying the two first variables first, then outer, then inner, then last.
Ex:
If the things being multiplied is (x+1) by (x-2), you would multiply "x" and "x" first.
#x*x=x^2#
#x*-2=-2x#
#1*x=x#
#1*-2=-2#
The final answer would be: #x^2-x-2#