Let u = R, a = {x | 6-x-x ^ 2 > 0}, B = {x | x-4 / x + 3} 1. Find a and B 2. Find a ∩ B, (CUA) ∪ B

Let u = R, a = {x | 6-x-x ^ 2 > 0}, B = {x | x-4 / x + 3} 1. Find a and B 2. Find a ∩ B, (CUA) ∪ B

Set a: X & # 178; + X-6 < 0, (x + 3) × (X-2) < 0, - 3 < x < 2, so set a: (- 3,2) set B: 1 / X (X & # 178; + 3x-4) ≥ 0,1 / X (x + 4) × (x-1) ≥ 0, ① x > 0 and X ≥ - 4 and X ≥ 1, we get x ≥ 1, ② x < 0 and X ≤ - 4 and X ≥ 1, there is no solution, ③ x < 0, X ≥ - 4, X ≤ 1