PSEB 9th Class Maths Solutions Chapter 4 Linear Equations in Two Variables Ex 4.4

Punjab State Board PSEB 9th Class Maths Book Solutions Chapter 4 Linear Equations in Two Variables Ex 4.4 Textbook Exercise Questions and Answers.

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

Question 1.
Give the geometric representation of y = 3 as an equation
(i) in one variable
If the equation y = 3 is treated as an equation in one variable, its graphical representation is a point on the number line as shown below:

(ii) in two variables.
If the equation 2x + 9 = 0, i.e., x = – $$\frac{9}{2}$$ is treated as an equation in one variable. its graphical representation is a point on the number line as shown below:
If the equation 2x + 9 = 0 is treated as an equation in two variables, it can be written as 2x + 0y + 9 = 0. Here, for any value of y, the value of x remains – $$\frac{9}{2}$$. Hence, we can easily take $$\left(-\frac{9}{2}, 0\right)$$, $$\left(-\frac{9}{2}, 2\right)$$, and $$\left(-\frac{9}{2}, 4\right)$$ as three solutions of the equation 2x + 9 = 0. Then, we plot these points in the Cartesian plane and draw the line passing through them. This line is the graph of the equation 2x + 9 = 0 as an equation in two variables. This graph is perpendicular to the x-axis and parallel to the y-axis.