Important Questions for Class 9 Chapter 4-Linear Equations in Two Variables

We have come up with sets of important CBSE questions across grades that are based on the latest syllabus and exam pattern. These sets of important questions in all the subjects will help you in dealing with Simple and difficult topics too.

Important questions based on NCERT syllabus for Class 9 Chapter 4 - Linear Equations in Two Variables:

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 Rs. x and that of a pen to be Rs. y).
Solution:
Let the cost of pen be y and the cost of notebook be x.
According to statement,
Cost of a notebook = twice the pen = 2y.
∴2y = x
⇒ x - 2y = 0
This is a linear equation in two variables to represent this statement.

Question 2: The taxi fare in a city is as follows: For the first kilometer, the fares is Rs 8 and for the subsequent distance it is Rs.5 per km. Taking the distance covered as x km and total fare as Rs y, write a linear equation for this information, and draw its graph.
Solution:
Total fare = y
Total distance covered = x
Fair for the subsequent distance after 1st kilo meter = Rs.5
Fair for 1st kilo meter = Rs. 8
According to statement,
y = 8 + 5(x-1)
⇒ y = 8 + 5x - 5
⇒ y = 5x + 3

Equation

Question 3: From the choices given below, choose the equation whose graphs are given in Fig. 4.6 and Fig.4.7.
Tbale

Solution:
In fig. 4.6,
Points are (0, 0), (-1, 1) and (1, -1).
∴ Equation (ii) x + y = 0 is correct as it satisfies all the value of the points.

In fig. 4.7,
Points are (-1, 3), (0, 2) and (2, 0).It can be observed that the coordinate
∴ Equation (iii) y = –x + 2 is correct as it satisfies all the value of the points