one

two

cháu hỏi gì  chẳng hiểu gì cả

tiếng anh là môn tiếng anh 

cái này thi thì tự làm nha

1 A

2 C

3 A

4 D

5 C

6 B

7 B

8 A

9 B

10 D

a: Xét ΔAMN và ΔCDN có 

NA=NC

\(\widehat{ANM}=\widehat{CND}\)

NM=ND

Do đó: ΔAMN=ΔCDN

b: Xét tứ giác AMCD có 

N là trung điểm của AC
N là trung điểm của MD

Do đó: AMCD là hình bình hành

Suy ra: CD//AM

hay CD//AB

5 since we last met our uncle

6 were pen pals 2 years ago

started being pen pals 2 years ago

7 not gone to London for 2 years

2 years since we last went to London

we went to London was 2 years ago

8 have never visited HN before

9 2 weeks since she last phoned home

10 seen his brother for nearly 20 years

11 seen our grandfather for 2 years

12 we went to the concert was a year ago

13 Linda talked to me was many years ago

14 we went to the beach was 10 years ago

15 taught English at this school since January 10th

16 I took photographs was 2 years ago

17 6 months since John last had his hair cut

18 we have seen this man here

19 never been to England before

20 the first time I have read a romantic story

21 she wrote to me was in March

22 taught the children in that remote village for 2 years

23 been married for 7 years

24 not written to me for years

Công thức đây nhé (Áp dụng làm thử đi)

Tỉ số giữa cạnh đối và cạnh huyền được gọi là sin của góc $\alpha$α, kí hiệu $\sin \alpha$sinα.
 Tỉ số giữa cạnh kề và cạnh huyền được gọi là côsin của góc $\alpha$α, kí hiệu $\cos \alpha$cosα.
 Tỉ số giữa cạnh đối và cạnh kề được gọi là tang của góc $\alpha$α, kí hiệu $\tan \alpha$tanα.
 Tỉ số giữa cạnh kề và cạnh đối gọi là côtang của góc $\alpha$α, kí hiệu $\cot \alpha$cotα.

Ai biết câu trả lời giúp em liền với ạ huhu

a, 

= \(\dfrac{13}{24}+\dfrac{-1}{16}\)

= \(\dfrac{23}{48}\)

b,

= \(\dfrac{7}{3}:\dfrac{7}{8}\)

= \(\dfrac{8}{3}-\dfrac{2}{5}\)

= \(\dfrac{34}{15}\)

c,

25%= \(\dfrac{1}{4}\)

= \(\dfrac{1}{4}-\dfrac{3}{2}+\dfrac{1}{2}\left(0,5=\dfrac{1}{2}\right).\dfrac{12}{5}\)

= \(\dfrac{1}{4}-\dfrac{3}{2}+\dfrac{6}{5}\)

= \(\dfrac{-5}{4}+\dfrac{6}{5}\)

= \(\dfrac{-1}{20}\)

a) \(\dfrac{13}{24}+\dfrac{11}{24}:\dfrac{-22}{3}\)

  =\(\dfrac{13}{24}+\dfrac{-1}{16}\)

  =\(\dfrac{26}{48}+\dfrac{-3}{48}\)

  =\(\dfrac{23}{48}\)

b) \(\left(\dfrac{5}{2}+\dfrac{-1}{6}\right):\dfrac{7}{8}-\dfrac{2}{5}\)

    =\(\left(\dfrac{15}{6}+\dfrac{-1}{6}\right):\dfrac{7}{8}-\dfrac{2}{5}\)

    =\(\dfrac{7}{3}:\dfrac{7}{8}-\dfrac{2}{5}\)

    =\(\dfrac{8}{3}-\dfrac{2}{5}\)

    =\(\dfrac{40}{15}-\dfrac{6}{15}\)

    =\(\dfrac{34}{15}\)

c) 25% -\(1\dfrac{1}{2}\) +0,5.\(\dfrac{12}{5}\)

 =\(\dfrac{1}{4}-\dfrac{3}{2}+\dfrac{1}{2}.\dfrac{12}{5}\)

 = \(\dfrac{1}{4}-\dfrac{3}{2}+\dfrac{6}{5}\)

 =\(\dfrac{-5}{4}+\dfrac{6}{5}\)

 =\(\dfrac{-5}{12}\)