NCERT Class 9 Solutions: Linear Equation in Two Variable (Chapter 4) Exercise 4.2 – Part 1
Linear equation
Q1 Which one of the following option is true, and why?
has

A unique solution

Only two solution

Infinitely many solutions
Solution:

Infinitely many solutions

Because a linear equation in two variables has infinitely many solutions. We keep changing the value of and solve the linear equation for the corresponding value of .
Q2 Write four solutions for each of the following equations:
Solution:
i)
For ,
Therefore, is a solution of this equation.
For ,
Therefore, is a solution of this equation.
For ,
Therefore, is a solution of this equation.
For ,
⇒
Therefore, is a solution of this equation.
Four solutions of is ,
ii)
For
Therefore, is a solution of this equation.
For ,
⇒
Therefore, is a solution of this equation.
For ,
Therefore, is a solution of this equation.
For
Therefore, is a solution of this equation.
Four solution of
iii)
For ,
Therefore, is a solution of this equation.
For
Therefore, is a solution of this equation.
For
Therefore, is a solution of this equation.
For
Therefore , is a solution of this equation.
Four solution of is