Відповіді §.5 - §.6 » §.6 (3.3-4)

7/√(-5x-1,5) –5x – 1,5 > 0 –5x > 1,5 x < –0,3 x ∈ (–∞; –0,3) √(16-0,8x) 16 – 0,8x ≥ 0 –0,8x ≥ –16 x ≤ 20 x ∈ (–∞; 20) (–∞; –0,3) ∪ (–∞; 20] = (–∞; 20] (–∞; –0,3) ∩ (–∞; 20] = (–∞; –0,3) 4. √(1 2/3 x+25 ) 12/3x + 25 ≥ 0. 5/3x ≥ –25. x ≥ –25 : 5/3. x ≥ 15. [–15; +∞). √(111-3x) 111 – 3x ≥ 0. –3x ≥ –111. x ≤ 37. (–∞; 37]. (–∞; 37] ∪ [–15; +∞) = (–∞;∞). (–∞; 37] ∩ [–15; +∞) = [–15; 37].