Tập nghiệm của bất phương trình (x^2-5x+6)/(x^2)-25leqslant 0 là A S=[-5;2]cup [3;5] B S=(-5;2]cup [3;5) C S=(-infty ;-5)cup (5;+infty ) D S=(-infty ;-5)cup [2;3]cup (5;+infty )

1. **Factor the numerator and denominator:** * * 2. **Find the critical points:** * The expression is equal to zero when or . * The expression is undefined when or .3. **Create a sign table:** | Interval | x - 2 | x - 3 | x - 5 | x + 5 | Expression | |---|---|---|---|---|---| | x 5 | + | + | + | + | + |4. **Identify the intervals where the expression is less than or equal to zero:** * The expression is less than or equal to zero when: * -5 < x ≤ 2 * 3 ≤ x < 55. **Combine the intervals:** * The solution is **(-5, 2] ∪ [3, 5)****Therefore, the correct answer is B.**