Identifying the Parts of an Expression

TERMS Each expression is made up of terms. A term can be a number, a variable, or a constant multiplied by a variable or variables. Each term in an algebraic expression is separated by + or – sign. 5x + 3y + 8 What are the terms? The terms are 5x, 3y and 8.

VARIABLES A variable is a symbol assigned to an unknown value. It is usually represented with letters such as x, y, or t. Variables are lower case letters!

Coefficients and Variable Parts In a term like 7x , there are two parts: the numerical part and the variable part The numerical part is given a special name—it is called the coefficient. 7 x Coefficient Variable

In the term 4y, what is the coefficient? What is the variable? In the term 17x, what is the coefficient? What is the variable? 4 is the coefficient and y is the variable. 17 is the coefficient and x is the variable.

That is, x has a coefficient of 1 . Also, x2 has a coefficient 1 . If you don't ‘see’ a coefficient, then it is 1. That is, x  has a coefficient of 1 . Also, x2 has a coefficient 1 . It's never necessary to write a coefficient of 1, because multiplication by 1 doesn't change anything.

Constants A term like “2”  that has no variable part is called a constant term, because it is constant—it never changes. It have a fixed value.

Conventional Way to Write Terms In any term, it is conventional to write the numerical coefficient first. You should write 4x, not x4.