37 C

38 B

39 D

40 A

37 C

38 C

39 A

40 D

36 C

37 A

38 B

39 D

40 B

36 A

37 A

38 A

39 B

40 D

Câu 48: B

Câu 44: D

\(AB=2.\dfrac{6.\sqrt{10^2-6^2}}{10}=9,6\left(cm\right)\)

ngu nhu cc ma doi giup

\(\left(3+8\right).4=44\)

\(\left(9+7\right).2=32\)

\(\left(8+7\right).?=75\Rightarrow?=\dfrac{75}{15}=...\)

1 This meal didn't cost as much as I though

2 I've never seen such a bad film

3 Is that the best you can do?

4 There is less dry in the North than there is in the south of England

5 She was not expected to be so beautiful

6 The meeting went more smoothly than it did last time

7 You lead 

8 Helen earns twice as much as I do

9 The other teams have gone less games than they 

4.

\(=\dfrac{4\left(\sqrt{7}-\sqrt{3}\right)}{\left(\sqrt{7}+\sqrt{3}\right)\left(\sqrt{7}-\sqrt{3}\right)}+\dfrac{2\left(\sqrt{7}+3\right)}{\left(\sqrt{7}-3\right)\left(\sqrt{7}+3\right)}\)

\(=\dfrac{4\left(\sqrt{7}-\sqrt{3}\right)}{4}+\dfrac{2\left(\sqrt{7}+3\right)}{-2}=\sqrt{7}-\sqrt{3}-\sqrt{7}-3\)

\(=-\sqrt{3}-3\)

5.

Hàm đồng biến khi \(2m>0\Leftrightarrow m>0\)

15: Pha dao động là pi+pi/2=3/2pi

=>Chọn C

14:

Khi t=1,25 thì \(x=2\cdot cos\left(2.5pi-\dfrac{pi}{6}\right)=1\)

=>Chọn A

15: Pha dao động là pi+pi/2=3/2pi

=>Chọn C

14:

Khi t=1,25 thì \(x=2\cdot cos\left(2.5pi-\dfrac{pi}{6}\right)=1\)

=>Chọn A

16: \(10t-\dfrac{3}{2}pi=\dfrac{2}{3}pi\)

=>10t=2/3pi+3/2pi=13/6pi

=>t=13/60pi

\(x=6\cdot cos\left(10\cdot\dfrac{13}{6}pi-\dfrac{3}{2}pi\right)\)

\(=6\cdot cos\left(\dfrac{2pi}{3}\right)=-3\)

=>Chọn C