Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

Class 9 Mathematics by Full Circle

Created by: Full Circle

Class 9 : Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

The document Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev is a part of the Class 9 Course Class 9 Mathematics by Full Circle.
All you need of Class 9 at this link: Class 9

Question 1. Give the geometric representations of y = 3 as an equation 
(i) in one variable 
(ii) in two variables
Solution: (i) y = 3 [An equation in one variable]
∵ y = 3 is an equation in one variable, i.e. y only.
∴ It has a unique solution y = 3 as shown on the number line shown here.

Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

The unique solution is a point.

(ii) y = 3 [An equation in two variables]
We can write y = 3 as
0.x + y = 3
Now, when x = 1, y = 3
when x = 2, y = 3
when x = 3, y = 3
We get the following table:

x
1
2
3
y
3
3
3

 

Plotting the ordered pairs (1, 3), (2, 3) and (3, 3) on a graph paper, we get a line AB as solution of 0 . x + y = 3, i.e. y = 3.

Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev


Question 2. Give the geometric representations of 2x + 9 = 0 as an equation (i) in one variable (ii) in two variables
Solution: (i) 2x + 9 = 0 [An equation in one variable]
We have: 2x + 9 = 0
⇒ 2x = –9
⇒ x = (-9/2)
which is a linear equation in one variable ‘x’ only. Its solution is the point (-9/2) on the number line as shown below.

Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

(ii) 2x + 9 = 0 [An equation in two variables]
We can write 2x + 9 = 0 as 2x + 0y + 9 = 0 or 2x = –9 + 0y
or  Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev
∴ When y = 1, Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev
When y = 2, Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev
When y = 3,  Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

Thus, we get the following table:

x
-9/2
-9/2
-9/2
y
1
2
3

 

Now, plotting the ordered pairs Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRevon a graph paper and joining them, we get a line PQ as solution of 2x + 9 = 0.

Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

Share with a friend

Complete Syllabus of Class 9

Dynamic Test

Content Category

Related Searches

Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

,

practice quizzes

,

MCQs

,

Semester Notes

,

Viva Questions

,

mock tests for examination

,

pdf

,

Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

,

Previous Year Questions with Solutions

,

past year papers

,

video lectures

,

shortcuts and tricks

,

Free

,

Summary

,

study material

,

Objective type Questions

,

Extra Questions

,

Sample Paper

,

Ex 4.4 NCERT Solutions - Linear Equations in Two Variables Class 9 Notes | EduRev

,

ppt

,

Exam

,

Important questions

;