<span>In an algebraic expression, terms are the elements separated by the plus or minus signs. This example has four terms, <span>3x2</span>, 2y, 7xy, and 5. Terms may consist of variables and coefficients, or constants.</span>
<span>Variables
In algebraic expressions, letters represent variables. These letters are actually numbers in disguise. In this expression, the variables are x and y. We call these letters "variables" because the numbers they represent can vary—that is, we can substitute one or more numbers for the letters in the expression.</span>
<span>Coefficients
Coefficients are the number part of the terms with variables. In <span>3x2 + 2y + 7xy + 5</span>, the coefficient of the first term is 3. The coefficient of the second term is 2, and the coefficient of the third term is 7.</span>
If a term consists of only variables, its coefficient is 1.
<span>Constants
Constants are the terms in the algebraic expression that contain only numbers. That is, they're the terms without variables. We call them constants because their value never changes, since there are no variables in the term that can change its value. In the expression <span>7x2 + 3xy</span> + 8 the constant term is "8."</span>
<span>Real Numbers
In algebra, we work with the set of real numbers, which we can model using a number line.</span>
