1.

If |x + 2| ≤ 9, then A.x ∈ (–7, 11) B. x ∈ [–11, 7] C. x ∈ (∞, –7) ∪ (11, ∞) D. x ∈ (–∞, –7) ∪ [11, ∞)

Answer»

B. x ∈ [-11, 7]

Given,

|x + 2| ≤ 9

There are two cases,

(x + 2) ≤ 9

⇒ x ≤ 7

⇒ x ∈ (-∞,7] [1]

And

-(x + 2) ≤ 9

⇒ -x – 2 ≤ 9

⇒ -x ≤ 11

⇒ x ≥ -11 [Multiplication by negative inverts the inequality sign]

⇒ x ∈ [-11, ∞) [2]

From [1] and [2], we get

⇒ x ∈ [-11, 7]



Discussion

No Comment Found

Related InterviewSolutions