## Key Equations

 perfect square trinomial ${\left(x+a\right)}^{2}=\left(x+a\right)\left(x+a\right)={x}^{2}+2ax+{a}^{2}$ difference of squares $\left(a+b\right)\left(a-b\right)={a}^{2}-{b}^{2}$

## Key Concepts

• A polynomial is a sum of terms each consisting of a variable raised to a nonnegative integer power. The degree is the highest power of the variable that occurs in the polynomial. The leading term is the term containing the highest degree, and the leading coefficient is the coefficient of that term.
• We can add and subtract polynomials by combining like terms.
• To multiply polynomials, use the distributive property to multiply each term in the first polynomial by each term in the second. Then add the products.
• FOIL (First, Outer, Inner, Last) is a shortcut that can be used to multiply binomials.
• Perfect square trinomials and difference of squares are special products.
• Follow the same rules to work with polynomials containing several variables.

## Glossary

binomial
a polynomial containing two terms
coefficient
any real number ${a}_{i}$ in a polynomial of the form ${a}_{n}{x}^{n}+\dots+{a}_{2}{x}^{2}+{a}_{1}x+{a}_{0}$
degree
the highest power of the variable that occurs in a polynomial
difference of squares
the binomial that results when a binomial is multiplied by a binomial with the same terms, but the opposite sign
any ${a}_{i}{x}^{i}$ of a polynomial of the form ${a}_{n}{x}^{n}+\dots+{a}_{2}{x}^{2}+{a}_{1}x+{a}_{0}$