# Are the following pair of sets equal ? Give reasons.

(i) A = {2, 3}, B = {x : x is solution of x² + 5x + 6 = 0}

(ii) A = { x : x is a letter in the word FOLLOW} B = { y : y is a letter in the word WOLF}

**Solution:**

**(i) **A = {2, 3}; B = {x : x is solution of x^{2} + 5x + 6 = 0}

The quadratic equation x^{2} + 5x + 6 = 0 can be solved as:

x^{2} + 3x + 2x + 6 = 0

x ( x + 3) + 2 ( x + 3) = 0

( x + 2)( x + 3) = 0

x = - 2 or x = - 3

Hence B = {- 2, - 3}

But A = {2, 3}.

Therefore, A ≠ B

**(ii)** A = {x : x is a letter in the word FOLLOW}

B = {y : y is a letter in the word WOLF}

Hence, A = {F, L, O, W}; B = {W , O, L, F}

The elements of sets A and B are same.

**Therefore, **

**A = B**

NCERT Solutions Class 11 Maths Chapter 1 Exercise 1.2 Question 5

## Are the following pair of sets equal? Give reasons. (i) A = {2, 3}; B = {x : x is solution of x² + 5x + 6 = 0} (ii) A = {x : x is a letter in the word FOLLOW} B = {y : y is a letter in the word WOLF}

**Summary:**

We are asked to check whether the following pair of sets are equal. We found that

(i) For A = {2, 3}, B = {x : x is solution of x^{2} + 5x + 6 = 0}, A ≠ B

(ii) For A = { x : x is a letter in the word FOLLOW} B = { y : y is a letter in the word WOLF}, A = B