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.