

A Very Short Algebra Glossary
There are six basic algebra terms you need to know for
the SAT. You also need to know these terms to understand what we’re
talking about in this section of the book.
Constant.
A quantity that does not change. A number.
Variable.
An unknown quantity written as a letter. A variable can
be represented by any letter in the English alphabet, most often x or y.
Variables may be associated with specific things, like x number
of apples or y dollars. Other times,
variables have no specific association, but you’ll need to manipulate
them to show that you understand certain algebraic principles.
Coefficient.
A coefficient is a number that appears next to a variable
and tells how many of the variable there are. In the term 4x, 4 is
the coefficient.
Equation.
Two expressions linked by an equal sign. Most
of the algebra on the SAT consists of solving equations.
Term.
The product of a constant and a variable. Or, a quantity
separated from other quantities by addition or subtraction. For
example, in the equation
the side to the left of the equal sign contains four terms {3x^{3},
2x^{2}, –7x,
4}, while the right side contains two terms {x,
–1}. (The constants, 4 and –1,
are considered terms because they are coefficients of variables
raised to the zero power: 4 = 4x^{0}.)
So every term, including constants, is the product of a constant
and a variable raised to some power.
Expression.
Any combination of terms. An expression can be as simple
as a single constant term, like 5, or as complicated as the sum
or difference of many terms, each of which is a combination of constants
and variables, such as {(x^{2} +
2)^{3} – 6x} ⁄ 7x^{5}. Expressions
don’t include an equal sign—this is what differentiates expressions
from equations. Expressions cannot be solved; they can only be simplified.
