A technique for distributing two binomials . The letters FOIL stand for First, Outer, Inner, Last. First means multiply the terms which occur first in each binomial. Then Outer means multiply the outermost terms in the product. Inner means multiply the innermost two terms. Last means multiply the terms which occur last in each binomial. Then simplify the product and combine any like terrms which may occur.
FF FO IF IL
However it is distributive property only and simplify version.
(x+3)(x+7)=(3+x)(7+x) but positions remain same First ,outer,inner ,last.
So we can not change IFOL or in any permutations.
Example: (x + 2)(x + 5) = x·x + x·5 + 2·x + 2·5
First Outer Inner Last
= x2 + 7x + 10