NCERT Class 9 Maths Chapter 4 Linear Equations in Two Variables Exercise 4.1


Chapter 4 Linear Equations in Two Variables Exercise 4.1

Question 1: The cost of a notebook is twice the cost of a pen. Write a linear equation in two variables to represent this statement.
(Take the cost of a notebook to be ₹x and that of a pen to be ₹y).
Answer:
Let the cost of a notebook = ₹x
and the cost of a pen = ₹y
According to the question,
Cost of a notebook =2(Cost of a pen)
i.e. x = 2(y) or x = 2y or x - 2y = 0

Therefore, the linear equation for this question will be x - 2y = 0.

Question 2: Express the following linear equations in the form ax + by + c = 0 and indicate the values of a, b and c in each case:
i) 2x + 3y = 9.3
ii) x - y/5 - 10 = 0
iii) -2x + 3y = 6
iv) x = 3y
v) 2x = -5y
vi) 3x + 2 = 0
vii) y - 2 = 0
viii) 5 = 2x
Answer:

i) We have 2x + 3y = 9.3
or (2)x + (3)y + (-9.3 ) = 0
Substituting it with ax + by + c = 0, we get a = 2, b = 3 and c= -9.3.

ii) We have x - y/5 - 10 = 0
or x + (- 15)/y + (10) = 0
Substituting it with ax + by + c = 0, we get, a = 1, b = -15 and c = -10

iii) We have -2x + 3y = 6 or (-2)x + (3)y + (-6) = 0
Substituting it with ax - by + c = 0, we get a = -2, b = 3 and c = -6.

iv) We have x = 3y or (1)x + (-3)y + 0 = 0.
Substituting it with ax + by + c = 0, we get a = 1, b = -3 and c = 0.

v) We have 2x = -5y or (2)x + (5)y + (0) = 0.
Substituting it with ax + by + c = 0, we get a = 2, b = 5 and c = 0.

vi) We have 3x + 2 = 0 or (3)x + (0)y + (2) = 0.
Substituting it with ax + by + c = 0, we get a = 3, b = 0 and c = 2.

vii) We have y - 2 = 0 or (0)x + (1)y + (-2) = 0.
Substituting it with ax + by + c = 0, we get a = 0, b = 1 and c = -2.

viii) We have 5 = 2x or 5 - 2x = 0 or (-2)x + (0)y + 5 = 0.
Substituting it with ax + by + c = 0, we get a = -2, b = 0 and c = 5.

No comments:

Post a Comment

Also read!

Click on any of the below text for additional links:

Class 6

Class 6 Computer Kips Solutions
Class 6 Gul Mohar English Solutions
→ Class 6 Map Pointing Solutions
Class 6 NCERT Civics Solutions
Class 6 NCERT Geography Solutions
Class 6 NCERT History Solutions
Class 6 NCERT Maths Solutions
Class 6 NCERT Science Solutions

Class 7

Class 7 Computer Kips Solutions
Class 7 Gul Mohar English Solutions
English Grammar Class 7
English Writing Skills Class 7
Class 7 Map Pointing Solutions
Class 7 NCERT Civics Solutions
Class 7 NCERT Civics Notes
Class 7 NCERT Civics Extra Questions
Class 7 NCERT Geography Solutions
Class 7 NCERT Geography Notes
Class 7 NCERT Geography Extra Questions
Class 7 NCERT History Solutions
Class 7 NCERT History Notes
Class 7 NCERT History Extra Questions
Class 7 NCERT Maths Solutions
Class 7 NCERT Science Solutions
Class 7 NCERT Science Notes
Class 7 NCERT Science Extra Questions

Class 8

Class 8 Kips Artificial Intelligence Solutions
Class 8 Gul Mohar English Solutions
English Grammar Class 8
English Writing Skills Class 8
Class 8 Map Pointing Solutions
Class 8 NCERT Civics Solutions
Class 8 NCERT Civics Notes
Class 8 NCERT Civics Extra Questions
Class 8 NCERT Geography Solutions
Class 8 NCERT Geography Notes
Class 8 NCERT Geography Extra Questions
Class 8 NCERT History Solutions
Class 8 NCERT History Notes
Class 8 NCERT History Extra Questions
Class 8 NCERT Maths Solutions
Class 8 NCERT Science Solutions
Class 8 NCERT Science Notes
Class 8 NCERT Science Extra Questions
Class 8 NCERT Science Exemplar
Class 8 NCERT Science MCQs

Class 9

Class 9 Kips Artificial Intelligence Solutions
Class 9 Map Pointing Solutions
Class 9 NCERT Civics Solutions
Class 9 NCERT Geography Solutions
Class 9 NCERT History Solutions
Class 9 NCERT Maths Solutions
Class 9 NCERT Science Solutions

Class 10

Class 10 Kips Artificial Intelligence Solutions
Class 10 NCERT English Solutions
→ Class 10 Map Pointing Solutions
Class 10 NCERT Civics Solutions
Class 10 NCERT Civics Notes
Class 10 NCERT Civics Extra Questions
Class 10 NCERT Geography Solutions
Class 10 NCERT Geography Notes
Class 10 NCERT Geography Extra Questions
Class 10 NCERT History Solutions
→ Class 10 NCERT History Notes
Class 10 NCERT History Extra Questions
Class 10 NCERT Maths Solutions
Class 10 NCERT Science Solutions
Class 10 NCERT Science Notes
Class 10 NCERT Science Extra Questions

Computer Languages

Python Basics

Extra Activities

Extra Activities

Extra Knowledge

Extra Information
General Knowledge
Historical Places in India
Latest technology
Physical Sciences
Facts

• Mathematics quick links
Mathematical Terms
Maths Tricks

Home Top