Bài 1: Cho ΔABC vuông tại A, đường cao AH, biết \(\frac{AB}{AC}=\frac{5}{6}\) và BC = 12cm. Tính BH và CH

Bài 2: Cho ΔCDE nhọn, đường cao Ch. Gọi M,N theo thứ tự là hình chiếu của H lên CD và CE. Chứng minh:

a) CD.CM = CE.CN

b) ΔCMN ∼ ΔCED

1. Most story will accept a credit card instead of cash (ALTERNATIVE)

2. You can avoid tooth decay by brusing your teeth regulary (PREVENT)

3. Some of Peter's expressions make me think of my brother (REMIND)

4. When do you think this bridge was built? (OLD)

5. That old typewriter is not worth repairing (POINTLESS)

6. They share a lot of hobbies and interests (COMMON)

7. This train should have left 30 minutes ago (MEANT)

8. The president arranged for me to use his chauffeur-driven whenever I liked (DISOSAL)

9. The painting is worth 25,000d (VALUED)

10. This passport can be used in most countries.

11. My bank manager and I get on togerther very well (TERMS)

12. That hotel is a bit too expensive for us, Iam afraid (REACH)

13. Absolute secrecy was crucial to the suceess of the mission

14. Immediately after hs arrival home a water-heater exploded.

15. Rite doesn't realize how serious her husband's operation is going to be.

16. A waiter spilled soup over Lydia's new address last night.

17. It was the goalkeeper that saved the match for us.

18. Tim insisted on being told the complete story.

19. Jane's husband wull be returning from South America quite soon.

20. The permit expires at the end of his mouth.

Giải các phương trình:

a) \(\sqrt{4x}=10\)

b) \(\sqrt{x^2-2x+1}=8\)

c) \(\sqrt{x^2-6+9}=\sqrt{1-6x+9x^2}\)

d) \(\sqrt{2x-5}=x-2\)

e) \(\sqrt{x^2-2x+1}=\sqrt{x+1}\)

g) \(\sqrt{x^2-9}-\sqrt{x-3}=0\)

h) \(\sqrt{x^2-4x+4}+\sqrt{x^2-6x+9}=1\)

i) \(\sqrt{\frac{2x-3}{x-1}}=2\)

l) \(x+y+12=4\sqrt{x}+6\sqrt{y-1}\)

m) \(\sqrt{x+3-4\sqrt{x-1}}+\sqrt{x+8+6\sqrt{x-1}}=5\)

n) \(\sqrt{x+\sqrt{2x-1}}+\sqrt{x-\sqrt{2x-1}}=\sqrt{2}\)

p) \(\sqrt{2x-1}+\sqrt{x-2}=\sqrt{x+1}\)

q) \(\sqrt{x-7}+\sqrt{9-x}=x^2-16x+66\)

r) \(3x^2+21x+18+2\sqrt{x^2+7x+7}=2\)

Hơi nhiều câu mong các cậu giải hộ mik :<

Tìm giá trị của x để:

a) \(\sqrt{x^2-6x+9}=3-x\)

b) \(\sqrt{4x^2-4x+1}=2x-1\)