Algebraic Expressions • Topic 1 of 3

Terms, Factors & Types of Expressions

What are Algebraic Expressions?

An algebraic expression is a combination of constants, variables, and mathematical operations (addition, subtraction, multiplication, division, exponents). For example: \(3x + 5\), \(2a^2 - 4ab + b^2\), \(7y - 3\)

What are Terms, Factors, and Coefficients?

  • Term: A single number, variable, or product of numbers and variables separated by \(+\) or \(-\) signs
  • Example: In \(4x^2 + 3xy - 7\), the terms are \(4x^2\), \(3xy\), and \(-7\)
  • Factor: Numbers or variables multiplied together to form a term
  • Example: In \(6xy\), factors are \(6\), \(x\), and \(y\)
  • Coefficient: The numerical factor of a term (the number multiplied by the variable)
  • Example: In \(5x^2\), the coefficient is \(5\)

Types of Algebraic Expressions:

TypeDefinitionNumber of TermsExamples
MonomialExpression with exactly one term1\(7x\), \(-3y^2\), \(5ab\), \(12\)
BinomialExpression with exactly two terms2\(x + y\), \(3a^2 - 2b\), \(4x^2 + 7\)
TrinomialExpression with exactly three terms3\(x^2 + 2x + 1\), \(a^2 - 2ab + b^2\)
PolynomialExpression with one or more terms1 or moreAll of the above are polynomials

Like Terms vs Unlike Terms:

  • Like terms: Terms with the same variables raised to the same powers
  • Example: \(3x^2\) and \(5x^2\) are like terms; \(2xy\) and \(7xy\) are like terms
  • Unlike terms: Terms with different variables or different exponents
  • Example: \(4x^2\) and \(4x^3\) are unlike terms; \(3x\) and \(3y\) are unlike terms

Real-life Example: Think of a shopping bill: \(5x\) (5 apples at \(x\) rupees each) \(+ 3y\) (3 bananas at \(y\) rupees each) \(+ 10\) (fixed packaging charge). Here \(5x\), \(3y\), and \(10\) are terms; \(5\) and \(3\) are coefficients.

Anatomy of an Algebraic Expression3x² − 5xy + 7Term 1: 3x²Term 2: −5xyTerm 3: +73x²↑ ↑ ↑CoeffVariableExponentTypes: Monomial (1 term), Binomial (2), Trinomial (3), Polynomial (many)Like terms share the same variable(s) and exponent(s)
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Worked Example
Example 1: Identify the terms, coefficients, and constant term in the expression \(7x^2 - 3xy + 5y - 9\)
Solution- Step 1: Terms are: \(7x^2\), \(-3xy\), \(5y\), and \(-9\) - Step 2: Coefficients: For \(7x^2\) → \(7\); For \(-3xy\) → \(-3\); For \(5y\) → \(5\) - Step 3: Constant term (term without variable): \(-9\)
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Worked Example
Example 2: Classify the following expressions as monomial, binomial, trinomial, or polynomial: (i) \(5x^3\), (ii) \(a^2 + 2ab + b^2\), (iii) \(3m - 4n\), (iv) \(x^3 + x^2 + x + 1\)
Solution- Step 1: \(5x^3\) has 1 term → **Monomial - Step 2: \(a^2 + 2ab + b^2\) has 3 terms → **Trinomial** (also a polynomial) - Step 3: \(3m - 4n\) has 2 terms → **Binomial - Step 4: \(x^3 + x^2 + x + 1\) has 4 terms → **Polynomial
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Worked Example
Example 3: From the expression \(4x^2y - 3xy^2 + 2x^2y - 5y + 7xy^2\), identify like terms and combine them.
Solution- Step 1: List all terms: \(4x^2y\), \(-3xy^2\), \(2x^2y\), \(-5y\), \(7xy^2\) - Step 2: Identify like terms: - Terms with \(x^2y\): \(4x^2y\) and \(2x^2y\) - Terms with \(xy^2\): \(-3xy^2\) and \(7xy^2\) - Term with \(y\) only: \(-5y\) (no like term) - Step 3: Combine \(x^2y\) terms: \(4 + 2 = 6\) → \(6x^2y\) - Step 4: Combine \(xy^2\) terms: \(-3 + 7 = 4\) → \(4xy^2\) - Step 5: Keep \(-5y\) as is - Step 6: Write simplified expression: \(6x^2y + 4xy^2 - 5y\)

Key Points

  • A term is a single part of an expression separated by \(+\) or \(-\) signs
  • A coefficient is the numerical factor multiplied by the variable(s) in a term
  • Monomial: 1 term | Binomial: 2 terms | Trinomial: 3 terms | Polynomial: 1 or more terms
  • Like terms have identical variable parts (same variables raised to same exponents)
  • Unlike terms cannot be combined through addition or subtraction
  • Constants are terms without any variables
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Tap an option to check your answer0 / 4
Q1.An expression with exactly one term is a:
Explanation: One term.
Q2.An expression with two terms is a:
Explanation: Two terms.
Q3.In $7x$, the coefficient is:
Explanation: $7$.
Q4.Like terms have the same variables with the same:
Explanation: Same powers.