NCERT Solution For Class 9, Maths, Chapter 4, Linear Equations In Two Variables, Exercise 4.2

NCERT Solution For Class 9, Maths, Chapter 4, Linear Equations In Two Variables, Exercise 4.2

NCERT Solution For Class 9, Maths, Chapter 4, Linear Equations In Two Variables, Exercise 4.2 is given below which are very important to study. With total four questions, this exercise basics of this chapter.

Class 9, Maths, Chapter 4, Exercise 4.2, Solutions

Q.1. Which one of the following options is true, and why? y = 3x + 5 has

(i) a unique solution,

(ii) only two solutions,

(iii) infinitely many solutions

Ans: Given equation is y = 3 x + 5

Let x=1, y = 3(1) + 5 = 3 + 5 = 8

Let x=2, y = 3 (2) + 5 = 6 + 5 = 11

Let x=3, y = 3 (3) + 5 = 9 + 5 = 14

Clearly, for different values of x, we get another value of y. Thus, the chosen value of x together with this value of y constitutes another solution of the given solution. So, there is no end to different solutions of a linear equation in two variables.

Therefore, the correct answer is option (iii) i.e., infinitely many solutions.

Q.2. Write four solutions for each of the following equations:

(i) 2x + y = 7

(ii) πx + y = 9

(iii) x = 4y

Ans:

Q.3. Check which of the following are solutions of the equation x – 2y = 4 and which are not:

(i) (0, 2)

(ii) (2, 0)

(iii) (4, 0)

(iv) $\left( \sqrt{2},4\sqrt{2} \right)$

(v) (1, 1)

Ans:

Q.4. Find the value of k, if x = 2, y = 1 is a solution of the equation 2x + 3y = k.

Ans:

NCERT Solutions For Class 9, Maths, Chapter 4, Linear Equations In Two Variables (All Exercises)