In mathematics, often the value of a certain number may be unknown. A variable is a symbol, usually a letter, which is used to represent an unknown number.
Some examples of variables are:
x, a, t, y, b
A term can be a number, a variable, or a number and variable combined by multiplication or division.
Some examples of terms are:
x, 8, 4y,
An expression can be term or a collection of terms separated by addition or subtraction operators. Some examples of expressions, with the numbers of terms, are listed below:
Expression
Number of Terms
Description
6x
1
A number multiplied by a variable. The number is always written first followed by the variable(s).
3w – 8
2
Terms separated by –
7b + 5t – 6
3
Terms separated by + and –
1
All multiplication and division, no + or – symbol
Example:
Determine the number of terms in the following expressions:
a) 5xyz
b) 3x + 2y – 2x + 6
Solution:
a) 5xyz has one term
b) 3x + 2y – 2x + 6 has four terms
Coefficients Of Algebraic Terms
The number (positive or negative) in the algebraic term is called the coefficient.
For example:
For the term 4x, 4 is the coefficient
For the term –7y, –7 is the coefficient
The coefficient of 1 in an algebraic term is usually not written.
For example:
1y can be written as simply y. So, 1y and y are the same.
Example:
Find the coefficient and variable of each of the following terms:
a) 0.2m
b) –3p
c) q
d) z
e)
Solution:
a) 0.2m (The coefficient is 0.2 and the variable is m)
b) –3p (The coefficient is –3 and the variable is p)
c) q (The coefficient is and the variable is q)
d) z (The coefficient is 1 and the variable is z)
e) (The coefficient is and the variable is x)
The following video will explain more of what is algebra, what are variables, constants, coefficients, terms, and expressions.