Linear Polynomials Exercise 2.5 Class 9 Maths NCERT Solutions

The Linear Polynomials Exercise 2.5 solutions cover all 3 questions from the new Ganita Manjari book. This set is about two-quantity linear relationships of the form y = ax + b, where you find the slope and the fixed part. Use these NCERT Solutions Class 9 Maths Chapter 2 Linear Polynomials Exercise 2.5 answers to follow each step.

• Questions solved: all 3 questions on the relation y = ax + b.
• Main skills: using two data points to find the slope a and the intercept b.
• Links to chapter: it prepares you to read slope and intercept from graphs in Exercise 2.6.

These solutions are prepared by subject teachers, matched to the current 2026-27 NCERT, and checked step by step so a Class 9 student can follow each line.

What Does Class 9 Maths Chapter 2 Linear Polynomials Exercise 2.5 Cover?

This exercise studies how one quantity depends on another through the rule y = ax + b. Here a is the slope, the change in y for each unit change in x, and b is the fixed part that stays the same. Each data point gives one equation, so two points give two equations. You subtract to remove b, solve for a, then find b. This is a core idea of Linear Polynomials. The same method works for any pair of data points drawn from a bill, a table, or a graph.

Video Walkthrough

Source: PW Class 9 - NEEV on YouTube

Linear Polynomials Exercise 2.5 Question Breakdown

The exercise has three questions, each with two known data points.

Sample Solved Question from Exercise 2.5

Here is Question 1, solved step by step, so you can see how two points fix a line.

Question: A platform charges a fixed fee plus a cost per module. For 10 modules the bill is 400; for 14 modules it is 500. If y = ax + b, find a and b.

Step 1. Turn each observation into an equation: 400 = 10a + b and 500 = 14a + b.

Step 2. Subtract the first from the second to remove b: 100 = 4a.

Step 3. Solve for the slope: a = 1004 = 25.

Step 4. Put a = 25 into 400 = 10a + b: 400 = 250 + b, so b = 150.

Final answer. a = 25 and b = 150, so y = 25x + 150.

How to Use These Linear Polynomials Exercise 2.5 Solutions

Write both data points as equations before you calculate. Then use the Collegedunia solution to check that your slope and intercept match.

• Always subtract to cancel the equal term first.
• Verify by putting the second point back into your final rule.
• Practise these before your Class 9 annual exam to build a strong base for Class 10.

More Class 9 Maths Linear Polynomials Exercise 2.5 Solutions

Use the table below to open the full chapter or any other exercise of Linear Polynomials.