1. Identifying the Parts of an Expression

2. 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.

3. 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!

4. 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

5. 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.

6. 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.

7. 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.

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