Variable

A variable is a placeholder for various numerical values. Any letter can be used. as a variable.
x+2

A number which is the power of another variable where the power is not zero is also a variable.
x2

Constant

A number having a fixed numerical value is called a constant.
Example – 2,4,⅗

Algebraic Expression

A combination of variables and constants, connected by the fundamental arithmetic operations i.e. addition, subtraction, multiplication and division is called an Algebraic expression.

Example
X+2 (sum of variable and constant)
a-9 (variable and constant are connected by subtraction)
2x-3

Check your concept
3y is an algebraic expression – Ture or False?

Terms

Various parts of an algebraic expression which are separated by – or + are called terms of the expression.

Example
4x – 2y + 6z is an algebraic expression consisting of 3\three terms.

Coefficient of a Term

Consider the term 6×4, 6 is called the numerical coefficient of x4 and x4 is the literal coefficient of 6.

Like Term

The terms having the same literal coefficient are called Like Term

3X4, 6×4,-9×4 are like terms

Unlike Term

The terms having the different literal coefficients are called UnLike Term
3X3, 6×4,-9×4 are unlike terms.

Polynomial Expression

An algebraic expression that contains one or more terms in which the variable has only non-negative integer powers is called Polynomial Expression.

Example:
x+y
x+y_z
4×2+2y+3

Type of Polynomial Expression

Monomial
An algebraic expression that contains only one term is called a monomial.
Example
-9
7
4×2

Binomial

An algebraic expression that contains two terms is called a binomial.
Example
x2 + 7
x2 – 7
x + 9

Trinomial

An algebraic expression that contains three terms is called a trinomial
Example

5x + 2y + 2
x2 + 5y + 3

Quadrinomial

An algebraic expression that contains four terms is called a quadrinomial.
Example
a2 + b2 + c2 + 3abc
ab + ac + ac + abc

Exercise

Find out the coefficient of each term for the below expression
x2y2 – 14x2y + 20y2x + 15xy

Solution