Let's solve in ℝ: |2u + 5| ≤ 7 |A| ≤ B is equivalent to -B ≤ A ≤ B -7 ≤ 2u + 5 ≤ 7 We add -5 to all three parts of the inequality -12 ≤ 2u ≤ 2 We divide all three parts by 2, which is positive -6 ≤ u ≤ 1 ▶Solution found: u ∈ [-6, 1]
