C Reading

1A

2C

3A

4C

5A

Có những câu bạn làm chưa đúng nên mình làm lại nhé

B.

I/ 3A 7A 10C 12C 14D 20B 

II/

1. unhealthy

3. successfully

4. performers

C.

I/ 1B 2C 3A 

Bn cho đáp án cho sắn đi, mk trả lời cho lẹ!!

dễ ợt thứ 5

it takes me six hours to go from vinh to ha noi.(khúc sau ko chắc lắm:)

cấu trúc là it+take_{(tùy theo dạng mà chia)}+S+thời gian+to V+O

It takes me sixhours to go Vinh to Ha Noi 

It takes me sixhours to go Vinh to Ha Noi

Bài 2:

n) Ta có: \(N=\dfrac{4}{2\cdot4}+\dfrac{4}{4\cdot6}+\dfrac{4}{6\cdot8}+...+\dfrac{4}{2014\cdot2016}\)

\(=2\left(\dfrac{2}{2\cdot4}+\dfrac{2}{4\cdot6}+\dfrac{2}{6\cdot8}+...+\dfrac{2}{2014\cdot2016}\right)\)

\(=2\left(\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{8}+...+\dfrac{1}{2014}-\dfrac{1}{2016}\right)\)

\(=2\cdot\left(\dfrac{1}{2}-\dfrac{1}{2016}\right)\)

\(=2\cdot\dfrac{1007}{2016}=\dfrac{1007}{1008}\)

o) Ta có: \(\dfrac{1}{18}+\dfrac{1}{54}+\dfrac{1}{108}+...+\dfrac{1}{990}\)

\(=\dfrac{1}{3\cdot6}+\dfrac{1}{6\cdot9}+\dfrac{1}{9\cdot12}+...+\dfrac{1}{30\cdot33}\)

\(=\dfrac{1}{3}\left(\dfrac{3}{3\cdot6}+\dfrac{3}{6\cdot9}+\dfrac{3}{9\cdot12}+...+\dfrac{3}{30\cdot33}\right)\)

\(=\dfrac{1}{3}\left(\dfrac{1}{3}-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{12}+...+\dfrac{1}{30}-\dfrac{1}{33}\right)\)

\(=\dfrac{1}{3}\left(\dfrac{1}{3}-\dfrac{1}{33}\right)\)

\(=\dfrac{1}{3}\cdot\dfrac{10}{33}=\dfrac{10}{99}\)

a) Ta có: \(\left(6\dfrac{4}{9}+3\dfrac{7}{11}\right)-4\dfrac{4}{9}\)

\(=\dfrac{58}{9}+\dfrac{40}{11}-\dfrac{40}{9}\)

\(=2+\dfrac{40}{11}=\dfrac{62}{11}\)

Bài 2:

b) Ta có: \(10\dfrac{1}{5}-5\dfrac{1}{2}\cdot\dfrac{60}{11}+3:15\%\)

\(=\dfrac{51}{5}-\dfrac{11}{2}\cdot\dfrac{60}{11}+3:\dfrac{3}{20}\)

\(=\dfrac{51}{5}-30+20\)

\(=\dfrac{51}{5}-10=\dfrac{1}{5}\)

c) Ta có: \(\dfrac{2}{3\cdot5}+\dfrac{2}{5\cdot7}+\dfrac{2}{7\cdot9}+...+\dfrac{2}{97\cdot99}\)

\(=\dfrac{1}{3}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{9}+...+\dfrac{1}{97}-\dfrac{1}{99}\)

\(=\dfrac{1}{3}-\dfrac{1}{99}\)

\(=\dfrac{32}{99}\)

Bài 2: 

d) Ta có: \(\dfrac{5}{7}\cdot\dfrac{5}{11}+\dfrac{5}{7}\cdot\dfrac{2}{11}-\dfrac{5}{7}\cdot\dfrac{14}{11}\)

\(=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)\)

\(=\dfrac{5}{7}\cdot\dfrac{-7}{11}\)

\(=-\dfrac{5}{11}\)

e) Ta có: \(\dfrac{-5}{7}\cdot\dfrac{2}{11}+\dfrac{-5}{7}\cdot\dfrac{9}{11}+1\dfrac{5}{7}\)

\(=\dfrac{-5}{7}\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}\)

\(=\dfrac{12}{7}-\dfrac{5}{7}=1\)

a) Ta có: \(19\dfrac{5}{8}:\dfrac{7}{12}+\left(-15\dfrac{1}{4}\right):\dfrac{7}{12}\)

\(=\dfrac{157}{8}\cdot\dfrac{12}{7}-\dfrac{61}{4}\cdot\dfrac{12}{7}\)

\(=\dfrac{12}{7}\left(\dfrac{157}{8}-\dfrac{61}{4}\right)\)

\(=\dfrac{12}{7}\cdot\dfrac{35}{8}=5\cdot\dfrac{3}{2}=\dfrac{15}{2}\)

A=>1.98+2.97+3.96+...+98.1

  =>(1+2+3+...+98)2

  =>(98+1):2.98.2

  =>9702

2010-0=2010:10+1=202

a) Xét \(\Delta MNP\) vuông tại M:

\(NP^2=MN^2+MP^2\left(Pytago\right).\\ \Rightarrow NP^2=5^2+12^2.\\ \Rightarrow NP^2=169.\\ \Rightarrow NP=13\left(cm\right).\)

b) Xét \(\Delta MNP\) vuông tại M:

MD là phân giác \(\widehat{NMP}\left(gt\right).\)

\(\Rightarrow\dfrac{ND}{DP}=\dfrac{MN}{MP}\) (T/c phân giác).

\(\Leftrightarrow\dfrac{ND}{ND+DP}=\dfrac{MN}{MP+MN}.\\ \Leftrightarrow\dfrac{ND}{NP}=\dfrac{MN}{MP+MN}.\\ \Rightarrow\dfrac{ND}{13}=\dfrac{5}{12+5}.\\ \Leftrightarrow\dfrac{ND}{13}=\dfrac{5}{17}.\\ \Rightarrow ND=\dfrac{65}{17}\left(cm\right).\\ \Rightarrow DP=NP-ND=13-\dfrac{65}{17}=\dfrac{156}{17}\left(cm\right).\)