Class 9 Math: Polynomials Important Exam Questions

Preparing for school exams or final CBSE boards requires practicing questions patterned after official grading schemes. We have compiled a list of crucial questions for Class 9 Polynomials to help you test your mastery.

Exam-Pattern Questions and Answers

Question 1 (EASY)

• Option 1:
• Option 2:
• Option 3:
• Option 4:

Solution Explanation & Steps: (b) (x + 1) and (3x - 4)

Question 2 (EASY)

• Option 1: 2, - 2
• Option 2: 2x
• Option 3: 0, - 2
• Option 4: 0

Solution Explanation & Steps: p(x) = (x - 2)2 - (x + 2)2 = x2 + 4 - 4x - (x2 + 4 + 4x) = x2 + 4 - 4x - x2 - 4 - 4x = -8x Now, p(x) = 0 ⇒ -8x = 0 ⇒ x = 0 Correct option is (d).

Question 3 (MEDIUM)

This is a descriptive problem. Work out all steps on paper before checking the solution.

Solution Explanation & Steps: We know that (x + y)3 = x3 + y3 + 3xy(x + y) x3 + y3 = (x + y)3 - 3xy(x + y) Now, 8x3 + 27y3 = (2x)3 + (3y)3 = (2x + 3y)3 - 3(2x)(3y)(2x + 3y) = 123 - 18 × 6 × 12 [Given 2x + 3y = 12 and xy = 6] = 1728 - 1296 = 432 Hence, 8x3 + 27y3 = 432

Grading Step-Marking Guidelines

Remember that teachers award partial marks for writing down formulas, stating the given variables, and drawing diagrams. Never leave a question blank on an exam. Write down the relevant formulas and initial substitution steps to secure partial credits.