NCERT Solutions for Class 9 Maths Chapter 4 Linear Equations in Two Variables Ex 4.4

# NCERT Solutions for Class 9 Maths Chapter 4 Linear Equations in Two Variables Ex 4.4

## NCERT Solutions for Class 9 Maths Chapter 4 Linear Equations in Two Variables Ex 4.4

NCERT Solutions for Class 9 Maths Chapter 4 Linear Equations in Two Variables Ex 4.4 are the part of NCERT Solutions for Class 9 Maths. Here you can find the NCERT Solutions for Class 9 Maths Chapter 4 Linear Equations in Two Variables Ex 4.4.

Ex 4.4 Class 9 Maths Question 1.
Give the geometric representations of y = 3 as an equation
(i) in one variable
(ii) in two variables

Solution:
(i)
y = 3
y = 3 is an equation in one variable, i.e., y only.
y = 3 is a unique solution on the number line as shown below:

(ii) y = 3
We can write y = 3 in two variables as 0.x + y = 3
Now, when x = 1, we have y = 3.

When x = 2, we have y = 3
When x = -1, we have y = 3
We get the following table:

 x 1 2 -1 y 3 3 3

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

Ex 4.4 Class 9 Maths 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
We have, 2x + 9 = 0

2x = – 9

x = 9/2
This is a linear equation in one variable, i.e., x only.

Therefore, x = 9/2 is a unique solution of 2x + 9 = 0.

The geometrical representation of 2x + 9 = 0 is shown below:

(ii) 2x + 9 = 0

We can write 2x + 9 = 0 in two variables as 2x + 0.y + 9 = 0
or x = −9/2 0.y/2
When y = 1, x = 9/2

When y = 2, x = 9/2

When y = 3, x = 9/2
Thus, we have the following table:

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

Now, plotting the ordered pairs (−9/2, 1), (−9/2, 2) and (−9/2, 3) on a graph paper and joining them, we get a line PQ as solution of 2x + 9 = 0.

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