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:
| Type | Definition | Number of Terms | Examples |
|---|---|---|---|
| Monomial | Expression with exactly one term | 1 | \(7x\), \(-3y^2\), \(5ab\), \(12\) |
| Binomial | Expression with exactly two terms | 2 | \(x + y\), \(3a^2 - 2b\), \(4x^2 + 7\) |
| Trinomial | Expression with exactly three terms | 3 | \(x^2 + 2x + 1\), \(a^2 - 2ab + b^2\) |
| Polynomial | Expression with one or more terms | 1 or more | All 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.