Trả lời 

\(\frac{19}{13}\)- \(\frac{6}{13}\)+ (-11) = 1 + (-11) = -10

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K mik nha

a, Ta có: \(\frac{23}{27}>\frac{23}{29}>\frac{22}{29}\)

\(\Rightarrow\frac{23}{27}>\frac{22}{29}\)

b, Ta có:

\(\frac{12}{25}< \frac{1}{2}\)

\(\frac{25}{49}>\frac{1}{2}\)

\(\Rightarrow\frac{12}{25}< \frac{25}{49}\)

1.Do you parents speak English.

v       My parents speak                English.

2.Sarah studies geography.

?                      Does Sarah study                                     geography?

3.Does Rischard live in London?

x                      Rischard doesn't live                                      in London.

4. Mr.Baker doesn't watch the news on TV

v                       Mr.Barker watches                                     the news on TV.

5.Those children don't do enough homework?

?                 Do those children do                                     enough homework?

6.My brother drinks fruit juice at break fast.

x                          My brother doesn't drinks                                   fruit juice at break fast.

1.Your parents speak English.

2.Does Sarah study geography?

3.Rischard doesn't live in London.

4.Mr.Baker watches the news on TV.

5.Do those children do enough homework?

6.My brother doesn't drink fruit juice at breakfast.

đề bài là j

cho mình hỏi

đề bài là j vậy

.........................

khó đọc quá 

\(A=\frac{1}{99}-\frac{1}{99.98}-\frac{1}{98.97}-\frac{1}{97.96}-...-\frac{1}{2.1}\)

\(=\frac{1}{99}-\left(\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{97.98}+\frac{1}{98.99}\right)\)

\(=\frac{1}{99}-\left(\frac{2-1}{1.2}+\frac{3-2}{2.3}+...+\frac{98-97}{97.98}+\frac{99-98}{98.99}\right)\)

\(=\frac{1}{99}-\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{97}-\frac{1}{98}+\frac{1}{98}-\frac{1}{99}\right)\)

\(=\frac{1}{99}-\left(1-\frac{1}{99}\right)\)

\(=\frac{-97}{99}\)