How to FOIL
F – first term in each bracket
O – outside terms
I – inside terms
L – last term
example:
(a+b)(a+b)
= 
In this example, the a from the first bracket is multiplied by the a in the second bracket, then the a in the first bracket is multiplied by the b in the second bracket. After that the b in the first bracket is multiplied by the a in the second bracket and lastly the b in the first bracket is multiplied by the b in the second bracket. This method can be used for any multiplying of two binomials.