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About Polynomials — Class 9 CBSE

Understand degree, zeroes of polynomials, remainder theorem, and factor theorem. This topic is part of the CBSE Class 9 mathematics syllabus (chapter: Chapter 2). On this page you can practice 60 questions across three difficulty levels — 20 easy, 20 medium, and 20 hard — each with a visual step-by-step solution, plus a timed 35-question mastery test with a live leaderboard. Worked examples and sample questions from the topic are below.

Polynomials — solved examples for Class 9 CBSE

Example 1easy

What is the degree of the polynomial 5x3+4x275x^3 + 4x^2 - 7?
  1. A)1
  2. B)2
  3. C)3
  4. D)5

Step-by-step solution

  1. The terms are 5x35x^3, 4x24x^2, and 7-7.
  2. The highest power of xx is 3.
    Degree=3\text{Degree} = 3

Answer: 3

Example 2medium

If (x2)(x - 2) is a factor of p(x)=x34x2+x+6p(x) = x^3 - 4x^2 + x + 6, which of the following is true?
  1. A)p(2)=0p(2) = 0
  2. B)p(2)=0p(-2) = 0
  3. C)p(2)=6p(2) = 6
  4. D)p(2)=6p(2) = -6

Step-by-step solution

  1. Factor Theorem: (xa)(x-a) is a factor of p(x)p(x) iff p(a)=0p(a) = 0.
  2. Since (x2)(x-2) is a factor, p(2)=0p(2) = 0.

Answer: p(2)=0p(2) = 0

Example 3hard

Factorise: x36x2+11x6x^3 - 6x^2 + 11x - 6
  1. A)(x1)(x2)(x3)(x-1)(x-2)(x-3)
  2. B)(x+1)(x2)(x3)(x+1)(x-2)(x-3)
  3. C)(x1)(x+2)(x3)(x-1)(x+2)(x-3)
  4. D)(x1)(x2)(x+3)(x-1)(x-2)(x+3)

Step-by-step solution

  1. p(1)=16+116=0p(1) = 1 - 6 + 11 - 6 = 0, so (x1)(x-1) is a factor.
  2. Dividing: x36x2+11x6=(x1)(x25x+6)x^3 - 6x^2 + 11x - 6 = (x-1)(x^2 - 5x + 6)
  3. x25x+6=(x2)(x3)x^2 - 5x + 6 = (x-2)(x-3)
  4. Final:
    (x1)(x2)(x3)(x-1)(x-2)(x-3)

Answer: (x1)(x2)(x3)(x-1)(x-2)(x-3)

Practice questions on Polynomials

  1. Q1.easy

    Which of the following is a monomial?
    1. A)x+1x + 1
    2. B)3x23x^2
    3. C)x2+x+1x^2 + x + 1
    4. D)xyx - y
    Show answer

    Answer: 3x23x^2

    Hint: A monomial has only one term.

  2. Q2.easy

    The zero of the polynomial p(x)=2x6p(x) = 2x - 6 is:
    1. A)3-3
    2. B)33
    3. C)66
    4. D)6-6
    Show answer

    Answer: 33

    Hint: Set p(x)=0p(x) = 0 and solve for xx.

  3. Q3.easy

    A polynomial of degree 2 is called a:
    1. A)Linear polynomial
    2. B)Quadratic polynomial
    3. C)Cubic polynomial
    4. D)Constant polynomial
    Show answer

    Answer: Quadratic polynomial

    Hint: Think about the prefix 'quad' relating to the number 2.

  4. Q4.medium

    Find the remainder when x3+3x2+3x+1x^3 + 3x^2 + 3x + 1 is divided by (x+1)(x + 1).
    1. A)8
    2. B)0
    3. C)1
    4. D)1-1
    Show answer

    Answer: 0

    Hint: By Remainder Theorem, remainder = p(1)p(-1).

  5. Q5.medium

    Factorise: x27x+12x^2 - 7x + 12
    1. A)(x3)(x4)(x-3)(x-4)
    2. B)(x2)(x6)(x-2)(x-6)
    3. C)(x+3)(x+4)(x+3)(x+4)
    4. D)(x1)(x12)(x-1)(x-12)
    Show answer

    Answer: (x3)(x4)(x-3)(x-4)

    Hint: Find two numbers whose product is 12 and sum is 7-7.

  6. Q6.medium

    Expand using identity: (2x+3y)(2x3y)(2x + 3y)(2x - 3y)
    1. A)4x29y24x^2 - 9y^2
    2. B)4x2+9y24x^2 + 9y^2
    3. C)2x23y22x^2 - 3y^2
    4. D)4x26y24x^2 - 6y^2
    Show answer

    Answer: 4x29y24x^2 - 9y^2

    Hint: Use (a+b)(ab)=a2b2(a+b)(a-b) = a^2 - b^2 with a=2xa = 2x and b=3yb = 3y.

  7. Q7.hard

    If x1x=3x - \frac{1}{x} = 3, find x31x3x^3 - \frac{1}{x^3}.
    1. A)27
    2. B)36
    3. C)18
    4. D)9
    Show answer

    Answer: 36

    Hint: Use the identity a3b3=(ab)(a2+ab+b2)a^3 - b^3 = (a-b)(a^2 + ab + b^2) or (ab)3=a33ab(ab)b3(a-b)^3 = a^3 - 3ab(a-b) - b^3.

  8. Q8.hard

    If a+b+c=0a + b + c = 0, find the value of a3+b3+c3a^3 + b^3 + c^3.
    1. A)00
    2. B)3abc3abc
    3. C)abcabc
    4. D)3abc-3abc
    Show answer

    Answer: 3abc3abc

    Hint: Use the identity a3+b3+c33abc=(a+b+c)(a2+b2+c2abbcca)a^3 + b^3 + c^3 - 3abc = (a+b+c)(a^2+b^2+c^2-ab-bc-ca).

  9. Q9.hard

    Factorise: x3+13x2+32x+20x^3 + 13x^2 + 32x + 20
    1. A)(x+1)(x+2)(x+10)(x+1)(x+2)(x+10)
    2. B)(x+1)(x+4)(x+5)(x+1)(x+4)(x+5)
    3. C)(x+2)(x+5)(x+2)(x+2)(x+5)(x+2)
    4. D)(x+1)(x+10)(x+2)(x+1)(x+10)(x+2)
    Show answer

    Answer: (x+1)(x+2)(x+10)(x+1)(x+2)(x+10)

    Hint: Try x=1x = -1 first to check if it's a zero.

These are 9 of the 60 questions available for Polynomials. Start practicing above to unlock visual solutions, AI coaching, and the topic leaderboard — completely free.