SATII数学考试快递——Polynomials
A polynomial is an expression that contains one or more algebraic terms, each consisting of a constant multiplied by a variable raised to a power greater than or equal to zero. For example, 
is a polynomial with three terms (the third term is 
. 
, on the other hand, is not a polynomial because x is raised to a negative power. A binomial is a polynomial with exactly two terms: 
and 
are both binomials.
The rest of this chapter will show you how to perform different operations on and with polynomials.
Multiplying Binomials
There is a very simple acronym that is useful in remembering how to multiply binomials. It is FOIL, and it stands for First, Outer, Inner, Last. This is the order that you multiply the terms of two binomials to get the right product.
For example, if asked to multiply the binomials:
You first multiply the first terms of each binomial:
Next, multiply the outer terms of the binomials:
Then, multiply the inner terms:
Finally, multiply the last terms:
Combine like terms and you have your product:
Here are a few more examples:
