Introduction to Linear Polynomials — Class 9 MCQs with Answers
Class 9 CBSE Mathematics · Chapter 2
90 practice questions · 30 Easy · 30 Medium · 30 Hard · Updated
Practise the most important Class 9 CBSE Mathematics questions from Chapter 2, "Introduction to Linear Polynomials". You get 9 timed quizzes made from 90 NCERT-based MCQs, with answers and explanations. The questions are split into 30 Easy, 30 Medium and 30 Hard. Warm up on the basics, then move on to the exam-level questions that top scorers in CBSE Board exams and the JEE & NEET foundation years get right.
To score well in "Introduction to Linear Polynomials", focus on fast problem-solving, formula recall and step-by-step working. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This helps you stay accurate when time is short, just as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on Introduction to Linear Polynomials, then move to Medium and Hard to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 9 Mathematics mastery score. Try the 6 sample questions below: tap an option to see the answer and a worked explanation. Sign in free to start practising.
Introduction to Linear Polynomials — important questions & MCQs with answers (Class 9 Mathematics)
6 solved questions from this chapter's difficulty levels, each with its answer and explanation. Tap an option to check yourself.
- Q1Easy
Which of the following is a polynomial?
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Answer: x² + 3x + 2
Explanation: A polynomial allows only whole-number, non-negative powers of the variable: x² + 3x + 2 has powers 2, 1, 0. √x is a power of ½, and 2/x, x⁻¹ carry negative powers, so none of those three qualify.
- Q2Easy
What is the degree of the polynomial 4x + 7?
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Answer: 1
Explanation: The degree of a polynomial is its highest power of the variable. In 4x + 7, x appears only to the power 1, so the degree is 1 — not the constant 7.
- Q3Medium
What is the zero of 5x − 15?
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Answer: 3
Explanation: Setting 5x − 15 = 0 gives 5x = 15, so x = 3. Dividing 15 by 5 gives 3, not the unsimplified constant 15 or its negative, −3.
- Q4Medium
Where does the line y = 2x + 3 meet the x-axis?
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Answer: (−3/2, 0)
Explanation: The line meets the x-axis where y = 0: solving 2x + 3 = 0 gives x = −3/2, so the point is (−3/2, 0). The y-intercept, (0, 3), is a different point, where the line meets the y-axis instead.
- Q5Hard
Taxi A charges 50 + 10x and taxi B charges 80 + 6x (x in km). For what distance is the cost equal?
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Answer: 7.5 km
Explanation: Set the two cost expressions equal and solve: 50 + 10x = 80 + 6x gives 4x = 30, so x = 7.5 km. Rounding 30/4 to a whole number instead of keeping the decimal 7.5 would lose precision.
- Q6Hard
For p(x) = ax + b, p(1) = 5 and p(−1) = 1. What is the value of a?
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Answer: 2
Explanation: Set up two equations from the given values: a + b = 5 and −a + b = 1. Subtracting the second from the first eliminates b and gives 2a = 4, so a = 2.
Key concepts: Introduction to Linear Polynomials (Class 9 Mathematics)
A polynomial is an algebraic expression built only from whole-number powers of a variable. This chapter classifies polynomials by degree and number of terms, finds their zeroes, reads them off a graph, and uses linear polynomials to model real situations such as cost, profit and break-even.
- Polynomial
- An expression of the form a₀ + a₁x + a₂x² + … in which every power of the variable is a whole number. Terms like 1/x or √x are therefore not allowed.
- Coefficient
- The number multiplying a power of the variable. In 7x − 4 the coefficient of x is 7, and −4 is the constant term (the coefficient of x⁰).
- Degree of a polynomial
- The highest power of the variable that appears with a non-zero coefficient. It fixes the polynomial's name and the maximum number of zeroes it can have.
- Linear polynomial
- A polynomial of degree 1, written ax + b with a ≠ 0. Its graph is always a straight line and it has exactly one zero.
- Constant polynomial
- A polynomial with no variable term, such as 5. Its degree is 0; the zero polynomial 0 is the exception, whose degree is undefined.
- Naming by number of terms
- One term is a monomial, two a binomial and three a trinomial — a separate classification from degree, which counts powers rather than terms.
- Value of a polynomial
- The number obtained by substituting a particular value of the variable. p(2) means replace every x by 2 and simplify.
- Zero of a polynomial
- A value of x that makes the polynomial equal 0. For the linear polynomial ax + b it is found by solving ax + b = 0.
- Graph of a linear polynomial
- A straight line. It meets the x-axis at exactly one point, and that point's x-coordinate is the polynomial's zero.
- y-intercept
- Where the graph crosses the y-axis, found by putting x = 0. For ax + b this is the constant term b.
- Slope
- The coefficient a in ax + b, measuring how steeply the line rises or falls. A positive a rises left to right, a negative a falls.
- Modelling with linear polynomials
- Real quantities that change at a steady rate — total cost, distance at constant speed, profit — can be written as ax + b and analysed with the same tools.
- Break-even point
- The value at which a cost polynomial and a revenue polynomial are equal, so profit is zero. It is the zero of the profit polynomial.
Start this chapter free
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Start this chapter free →Introduction to Linear Polynomials — FAQs
What are the key concepts in Class 9 Mathematics Introduction to Linear Polynomials?+
A polynomial is an algebraic expression built only from whole-number powers of a variable. This chapter classifies polynomials by degree and number of terms, finds their zeroes, reads them off a graph, and uses linear polynomials to model real situations such as cost, profit and break-even. Key ideas include Polynomial, Coefficient, Degree of a polynomial, Linear polynomial, Constant polynomial, Naming by number of terms.
What does Class 9 Mathematics Chapter 2 (Introduction to Linear Polynomials) cover on XamBaaz?+
It has 90 NCERT-based MCQs on "Introduction to Linear Polynomials": 30 Easy, 30 Medium and 30 Hard. Together they make 9 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE Board exams and the JEE & NEET foundation years.
Are these "Introduction to Linear Polynomials" questions free to practise?+
Yes. Sign in with Google to practise "Introduction to Linear Polynomials" free. Full unlimited access is ₹999/year. One year from the day you pay. You stay in Class 9 till 31 March; on 1 April your account moves up to Class 10 and the rest of your year carries over. No chapter is charged separately.
How should I revise "Introduction to Linear Polynomials" for the exam?+
Start with the Easy quiz to check your basics, then try Medium and Hard to practise applying them. There are 9 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "Introduction to Linear Polynomials" MCQs available with answers?+
Yes. 6 sample questions are on this page with answers: tap an option, or "Show answer", to see the correct option and a step-by-step explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "Introduction to Linear Polynomials" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from Introduction to Linear Polynomials (Class 9 Mathematics)?+
The questions that matter most test Polynomial, Coefficient, Degree of a polynomial, Linear polynomial, Constant polynomial, Naming by number of terms. This page shows 6 solved important MCQs with answers and explanations. Sign in to practise all 90 questions on the chapter as timed quizzes.
Is there an online quiz for Introduction to Linear Polynomials?+
Yes — Class 9 Mathematics Introduction to Linear Polynomials has timed online quizzes at Easy, Medium and Hard levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.