Algebraic Expressions (NCERT Ch. 12)

• Form algebraic expressions from statements, and identify terms, factors, and coefficients.
• Distinguish monomials, binomials, trinomials, and polynomials.
• Add and subtract algebraic expressions by combining like terms.
• Evaluate expressions for given values of variables.

1. A term is a single number, variable, or product/quotient of numbers and variables (e.g., 3x, -5, 2xy).
2. The coefficient is the numerical factor of a term (in 5x, the coefficient is 5).
3. Like terms have the same variable(s) raised to the same power (3x and 7x are like terms; 3x and 3x² are not).
4. Only like terms can be added or subtracted directly.
5. Monomial (1 term), binomial (2 terms), trinomial (3 terms), polynomial (many terms).

Simplify: (3x + 5y) + (2x - 3y)

Combine like terms: (3x + 2x) + (5y - 3y) = 5x + 2y

• Adding unlike terms directly (3x + 2y is NOT 5xy).
• Forgetting to distribute a negative sign when subtracting an expression in brackets.
• Confusing coefficient with exponent.

• Identify the coefficient of x in the term 7x.
• Simplify: 4a + 3b - 2a + b.

Open the Practice tab for graded questions on Algebraic Expressions (NCERT Ch. 12).