Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.6 Solutions: Introduction to Linear Polynomials
Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.6 Solutions cover graph-based questions from Introduction to Linear Polynomials. This exercise helps students draw graphs of linear equations and understand the role of a and b in equations of the form y = ax + b.
In this exercise, students draw and study lines such as y = 4x, y = −6x, y = 3x − 1 and y = −2x − 3. The main learning is to observe how a and b work in y = ax + b. The value of a controls the slope or steepness of the line, while b tells where the line cuts the y-axis. Through these Class 9 Maths Chapter 2 Exercise 2.6 Solutions, students also understand why lines with the same slope are parallel and how positive and negative slopes change the direction of a graph.
Key Takeaways
Graph of a Line: A linear equation gives a straight-line graph.
Slope: The value of a in y = ax + b controls steepness and direction.
Y-intercept: The value of b shows where the line cuts the y-axis.
Parallel Lines: Lines with the same slope and different intercepts are parallel.
Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.6 Solutions Structure 2026
| Exercise No. | Topic | Question Count |
| Exercise 2.6 | Positive slopes through origin | 1 |
| Exercise 2.6 | Negative slopes through origin | 1 |
| Exercise 2.6 | Opposite slopes | 1 |
| Exercise 2.6 | Same slope and different intercepts | 1 |
| Exercise 2.6 | Parallel and non-parallel line comparison | 1 |
Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.6 Solutions
Ganita Manjari Class 9 Chapter 2 Exercise 2.6 belongs to the section on visualising linear relationships. It builds on earlier ideas of linear patterns and y = ax + b Class 9 by showing how equations appear on the coordinate plane. Students practise choosing points, plotting straight lines, comparing slopes, identifying y-intercepts and recognising parallel lines.
Here:
- a is the slope of the line.
- b is the y-intercept.
- If a > 0, the line slopes upward.
- If a < 0, the line slopes downward.
- Lines with the same slope and different y-intercepts are parallel.
These Class 9 Maths graph of linear equation answers help students understand how graphs of linear equations behave.
Exercise 2.6 Question 1
Draw the graphs of the following sets of lines. In each case, reflect on the role of ‘a’ and ‘b’.
(i) y = 4x, y = 2x, y = x
Solution:
All three equations are of the form:
y = ax + b
Here, b = 0 for all three lines. So, all lines pass through the origin (0, 0).
Points for drawing the graphs
| Equation | Point 1 | Point 2 | Slope a | y-intercept b |
| y = 4x | (0, 0) | (1, 4) | 4 | 0 |
| y = 2x | (0, 0) | (1, 2) | 2 | 0 |
| y = x | (0, 0) | (1, 1) | 1 | 0 |
Observation
The line y = 4x is the steepest because it has the greatest slope. The line y = x is the least steep among the three.
Answer: All three lines pass through the origin. As a increases from 1 to 4, the line becomes steeper.
(ii) y = −6x, y = −3x, y = −x
Solution:
All three equations are of the form:
y = ax + b
Here, b = 0, so all lines pass through the origin.
Points for drawing the graphs
| Equation | Point 1 | Point 2 | Slope a | y-intercept b |
| y = −6x | (0, 0) | (1, −6) | −6 | 0 |
| y = −3x | (0, 0) | (1, −3) | −3 | 0 |
| y = −x | (0, 0) | (1, −1) | −1 | 0 |
Observation
Since the slopes are negative, all three lines slope downward from left to right. The line y = −6x is the steepest because its slope has the greatest magnitude.
Answer: All three lines pass through the origin and slope downward. As the magnitude of a increases, the line becomes steeper.
(iii) y = 5x, y = −5x
Solution:
Both equations have b = 0, so both lines pass through the origin.
Points for drawing the graphs
| Equation | Point 1 | Point 2 | Slope a | y-intercept b |
| y = 5x | (0, 0) | (1, 5) | 5 | 0 |
| y = −5x | (0, 0) | (1, −5) | −5 | 0 |
Observation
The lines have slopes of equal magnitude but opposite signs. So, y = 5x slopes upward and y = −5x slopes downward. They are mirror images of each other in the x-axis.
Answer: Both lines pass through the origin. y = 5x shows positive slope, while y = −5x shows negative slope.
(iv) y = 3x − 1, y = 3x, y = 3x + 1
Solution:
All three equations have the same slope:
a = 3
But their y-intercepts are different:
- For y = 3x − 1, b = −1
- For y = 3x, b = 0
- For y = 3x + 1, b = 1
Points for drawing the graphs
| Equation | Point 1 | Point 2 | Slope a | y-intercept b |
| y = 3x − 1 | (0, −1) | (1, 2) | 3 | −1 |
| y = 3x | (0, 0) | (1, 3) | 3 | 0 |
| y = 3x + 1 | (0, 1) | (1, 4) | 3 | 1 |
Observation
All three lines have the same slope, so they are parallel. The value of b shifts the line up or down.
Answer: The three lines are parallel because their slope is the same. Changing b shifts the line without changing its steepness.
(v) y = −2x − 3, y = −2x, y = 2x + 3
Solution:
The equations are:
- y = −2x − 3
- y = −2x
- y = 2x + 3
Points for drawing the graphs
| Equation | Point 1 | Point 2 | Slope a | y-intercept b |
| y = −2x − 3 | (0, −3) | (1, −5) | −2 | −3 |
| y = −2x | (0, 0) | (1, −2) | −2 | 0 |
| y = 2x + 3 | (0, 3) | (1, 5) | 2 | 3 |
Observation
The lines y = −2x − 3 and y = −2x have the same slope −2, so they are parallel. Their y-intercepts are different, so they cut the y-axis at different points.
The line y = 2x + 3 has positive slope, so it rises from left to right and is not parallel to the first two lines.
Answer: y = −2x − 3 and y = −2x are parallel. y = 2x + 3 has positive slope and is not parallel to them.
Final Answers for Exercise 2.6
| Question | Final Answer |
| 1(i) y = 4x, y = 2x, y = x | All pass through origin; larger positive slope means steeper upward line |
| 1(ii) y = −6x, y = −3x, y = −x | All pass through origin; larger negative slope magnitude means steeper downward line |
| 1(iii) y = 5x, y = −5x | Same steepness but opposite directions |
| 1(iv) y = 3x − 1, y = 3x, y = 3x + 1 | Same slope, different y-intercepts; lines are parallel |
| 1(v) y = −2x − 3, y = −2x, y = 2x + 3 | First two lines are parallel; third line has positive slope |
Concept Used in Introduction to Linear Polynomials Exercise 2.6
Introduction to Linear Polynomials Exercise 2.6 focuses on the graph of a linear equation. A linear equation in the form y = ax + b gives a straight line.
Important points:
- a represents the slope of the line.
- b represents the y-intercept.
- If b = 0, the line passes through the origin.
- If a > 0, the line rises from left to right.
- If a < 0, the line falls from left to right.
- A larger absolute value of a makes the line steeper.
- Lines with the same slope and different y-intercepts are parallel.
These ideas are central to slope and y-intercept Class 9 and help students understand linear equation graph Class 9 questions.
About Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.6
Ganita Manjari Class 9 Chapter 2 Exercise 2.6 appears in the section “Visualising Linear Relationships”. It comes after students learn linear patterns, linear growth, linear decay and equations of the form y = ax + b.
These Class 9 Maths Chapter 2 Exercise 2.6 Solutions prepare students for:
- drawing graphs of linear equations,
- identifying slope,
- identifying y-intercept,
- comparing steepness,
- recognising parallel lines,
- and understanding graph-based linear polynomial Class 9 questions.
NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2
| Section | NCERT Solutions |
| Class 9 Maths Ganita Manjari 2026 | NCERT Class 9 Maths Ganita Manjari 2026 |
| Chapter 2 | NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 |
| Exercise 2.1 | NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.1 |
| Exercise 2.2 | NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.2 |
| Exercise 2.3 | NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.3 |
| Exercise 2.4 | NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.4 |
| Exercise 2.5 | NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.5 |
| Exercise 2.6 | NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 Exercise 2.6 |
| End of Chapter Exercises | NCERT Solutions for Class 9 Maths Ganita Manjari Chapter 2 End of Chapter Exercises |
FAQs (Frequently Asked Questions)
Choose any two values of x, find the corresponding y-values, plot the two points and join them with a straight line. For example, for y = 3x + 1, use points (0, 1) and (1, 4).
They pass through the origin because their y-intercept is 0. In equations of the form y = ax, when x = 0, y = 0, so the line passes through (0, 0).
Compare the absolute value of the slope. The larger the value of |a|, the steeper the line. For example, y = 4x is steeper than y = 2x.
Two lines are parallel when they have the same slope but different y-intercepts. For example, y = 3x − 1, y = 3x and y = 3x + 1 are parallel because all have slope 3.
When the slope is negative, the line falls from left to right. For example, y = −6x, y = −3x and y = −x all slope downward because their slopes are negative.