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SAI International School
CLASS-VII

Mathematics
CHAPTER-12: Algebraic Expressions
Lesson Notes- 12.1

SUBTOPIC: Terms of an algebraic expression, monomials,
binomials, trinomials, polynomials, finding value of expression

Introduction: An algebraic expression is an expression built up from integer

constants, variables, and the algebraic operations like addition, subtraction,
multiplication, division, etc.

 A variable can take any value. Its value is not fixed.

Ex: x, y, z, p, q… etc are variables.
 A constant has a fixed value.

Ex: 10, -20, 100, etc. are constant.

 Now, we combine variables and constants to make algebraic expressions.
Ex: 2x + 5, 7y – 10, etc are algebraic expressions.

 An algebraic expression 2x + 5 is formed as:

First the variable x is multiplied to constant 2 and then adding the constant 5

to the product.

Terms of an expression: A term can be a signed number, a variable, or a

constant multiplied by a variable or variables.

 These are separated by mathematical operations.
 Terms are added to form an expression.

Ex- Terms 3x and 7 are added to form the expression 3x + 7.

Factors of a term: A term is a product of its factors.

Coefficient: The numerical factor is said to be the numerical coefficient or simply
the coefficient of the term.