Question

Solve the inequality

|2k + 1| ≥ 5

Answer 1

k∈(-∞;-3]∪[2;+∞).

Explanation:

step 1) if 2k+1>0, then

2k+1≥5; ⇔ k≥2;

step 2) if 2k+1<0, then

2k+1≤-5; ⇔ k≤-3;

step 3) finally, k∈(-∝;-3]∪[2;+∞).