If A = {x ∈ Z : x² + 3x + 2 = 0} and B = {-2, -1}, which relation is correct?
Answer and explanation
Correct answer: A = B
Factor the quadratic expression: x² + 3x + 2 = (x + 1)(x + 2). Therefore, the equation is satisfied when x = -1 or x = -2. Since both values are integers, A = {-1, -2}. Set order is irrelevant, so {-1, -2} = {-2, -1} = B. Hence A = B. The other options either use incorrect roots, claim no solutions, or incorrectly describe a two-element set as infinite.
Frequently asked questions
What is the correct answer to this question?
A = B
Why is this the correct answer?
Factor the quadratic expression: x² + 3x + 2 = (x + 1)(x + 2). Therefore, the equation is satisfied when x = -1 or x = -2. Since both values are integers, A = {-1, -2}. Set order is irrelevant, so {-1, -2} = {-2, -1} = B. Hence A = B. The other options either use incorrect roots, claim no solutions, or incorrectly describe a two-element set as infinite.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: The Empty Set, Finite and Infinite Sets, Equal Sets.
