# Give the geometric representations of 2x + 9 = 0 as an equation

(i) in one variable

(ii) in two variables

**Solution:**

(i) 2x + 9 = 0

2x = - 9

x = - 9/2

x = - 4.5

Hence, in one variable 2x + 9 = 0 represents a point as shown in the following figure.

(ii) We know that 2x + 9 = 0 can be written as 2x + 0y + 9 = 0 as a linear equation in two variables x and y.

Value of y is always 0. However, x must satisfy the relation 2x + 9 = 0 i.e. x = - 9/2 = - 4.5

Hence,

- When, y = 0, we get x = - 4.5
- When y = 2, we get x = - 4.5
- When y = -2, we get x = - 4.5

Therefore, plotting the points and on joining them we get the graph AB as a line parallel to the y-axis at a distance of 4.5 units on the left of the y-axis. It is a collection of all points of the plane, having their x-coordinate as 4.5.

**Video Solution:**

## Give the geometric representations of 2x + 9 = 0 as an equation (i) in one variable (ii) in two variables

### NCERT Solutions Class 9 Maths - Chapter 4 Exercise 4.4 Question 2:

**Summary:**

In one variable, 2x + 9 = 0 represents a point and in two variables, 2x + 9 = 0 represents a straight line passing through the point (- 9/2, 0) and parallel to the y-axis.