Cho hai tập hợp 𝐴 = [−1; 3);𝐵 = [𝑎; 𝑎 + 3]. 𝑇ì𝑚 𝑎 ∈ 𝑅 𝑡ℎì 𝐴 ∩ 𝐵 = ∅ ?
A.$\left\{\begin{array}{l}a\ge 3\\ a<4\end{array}\right.$
B.$\left\{\begin{array}{l}𝑎 > 3\\ 𝑎 < -4\end{array}\right.$

C.$\left\{\begin{array}{l}𝑎 \ge 3\\ 𝑎 \le -4\end{array}\right.$

D.$\left\{\begin{array}{l}𝑎 > 3\\ 𝑎 \le -4\end{array}\right.$

Cho ba tập hợp 𝐴 = [−2; 4];𝐵 = {𝑥 ∈ 𝑅, 0 ≤ 𝑥 < 4}; 𝐶 = {𝑥 ∈ 𝑅, |𝑥| > 1}. Khi đó :
A. 𝐴 ∩ 𝐵 ∩ 𝐶 = (1; 4)

B. 𝐴 ∩ 𝐵 ∩ 𝐶 = [1; 4]
C. 𝐴 ∩ 𝐵 ∩ 𝐶 = (1; 4]

D. 𝐴 ∩ 𝐵 ∩ 𝐶 = [1; 4)

Cho hai tập hợp 𝐴 = {𝑥 ∈ 𝑍, (𝑥 + 3)($x^2$ − 3) = 0} và 𝐵 = {𝑥 ∈ 𝑅, $x^2$ + 6 = 0}. Khi đó :

A. B \ A = B

B. 𝐴 ⊂ 𝐵

C. A \ B = A

D. 𝐴 ∩ 𝐵 = A

6. My house...................broken into last night.
A. are
В. is
C. was
D. were
7. The details should..................carefully.
C. was checked
B. check

A. is checked
D. be checked
8. If Mary doesn't improve in math, we..................have to find a tutor for her.
A. will
В. can
C. should
D. would
9. The journey to the village is very...........................
B. interesting
A. interested
C. disinterested
D. interest
10. I don't like using the internet because it has some.........................................
A. benefits
B. advantages
C. limitations
D. disadvantage

Tìm x biết

1. (x – 4)2 - 36 = 0

2. (x + 8)2 = 121

3. x2 + 8x + 16 = 0

4. 4x2 – 12x = -