2)Cho tam giác ABC vuông tại A, đường cao AH.

a) Biết AB=4cm, AC=4\(\sqrt{3}\) . Giải tam giác ABC.

b) Kẻ HD, He lần lượt vuông góc với AB,AC (D thuộc AB, E thuộc AC). Chứng minh BD.DA+CE.EA=\(AH^2\) 

c) Lấy điểm M nằm giữa E và C, kẻ AI vuông góc với MB tại I. Chứng minh sin^AMB.sin^ACB=\(\dfrac{HI}{CM}\)

bài 3 : Cho biểu thức:A=\(\left(\dfrac{\sqrt{x}}{\sqrt{x}-1}-\dfrac{1}{x-\sqrt{x}}\right):\dfrac{\sqrt{x}+1}{\sqrt{x}+2}\) và B=\(\dfrac{\sqrt{x}}{\sqrt{x}-3}\) với x>0, x≠1,x≠9.

a) Tính giá trị biểu thức B khi x=36.

b) Tìm x để B>\(\dfrac{1}{2}\)

c) Rút gịn biểu thức A.

d) Tìm giá trị x nguyên nhỏ nhất để biểu thức P=A.B nguyên.

bài 3 : Cho biểu thức:A=\(\left(\dfrac{\sqrt{x}}{\sqrt{x}-1}-\dfrac{1}{x-\sqrt{x}}\right):\dfrac{\sqrt{x}+1}{\sqrt{x}+2}\) và B=\(\dfrac{\sqrt{x}}{\sqrt{x}-3}\) với x>0, x≠1,x≠9.

a) Tính giá trị biểu thức B khi x=36.

b) Tìm x để B>\(\dfrac{1}{2}\)

c) Rút gịn biểu thức A.

d) Tìm giá trị x nguyên nhỏ nhất để biểu thức P=A.B nguyên.

a) \(\sqrt{4x-8}-12\sqrt{\dfrac{x-2}{9}}=-1\)

b) \(\left(2\sqrt{x}+1\right)\left(\sqrt{x}-2\right)=7\)

a)\(\sqrt{4x-8}-12\sqrt{\dfrac{x-2}{9}}=-1\)

b)\(\left(2\sqrt{x}+1\right)\left(\sqrt{x}-2\right)=7\)

4.Use your ideo to complete the sentences. Use a noun (this box etc) or a pronun (it/them etc). +the word in brackets(away/ up etc)

2. Turn___________ when you're not using it. (off)

3. It look me five days to get___________.(over)

4. This building is too old te be safe. They are going to___________.(down)

5. He has finished his college and is going to apply___________.(for)

6. He's thinking of  travelling to the USA, so he want to find___________.(out about)

7. I'd like to know who you are and where you live. Please put___________ here.(down)

8. Mary has failed her driving test. We need to give her a call to cheer___________.(up)

3.Fill the gap to complete phrasal verds in each sentence.

2. Why did she________ down your invitation?

3. I've________up a meeting for Friday.

4. The school was too old, so they decided to________it down and build a new one instead.

5. It' time for us to________ up for the big reception.

6. You should________ over before you reach an improtant decision.

7. Can I________ you around our company?

8. We waited and waited but they didn't________up until 5p.m.

VI.Complete the second sentence so that it has the same meanting as the first one.

4. She sings better than anyboby else in the class.

->She in_________________________________

5. Munnar is prettier than most other hill stations in India.

-> Munnar is_________________________________

6. Mary thinks Melbourne is the most "liveable" city in Australia.

-> Mary thinks Melbourne_________________________________

7. Lifestyle in Malaysia is the same as Thailand.

->Lifestyle in Malaysia is_________________________________

8. Beijing is much busier than Ho Chi Minh City.

-> Ho Chi Minh City isn't_________________________________

caau28:   Giải phương trình \(\sqrt{2x+5}-\sqrt{3x-5}=2\)