Tính :

a) A= \(\dfrac{1}{2010.2009}-\dfrac{1}{2009.2008}-...-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)

b) B= 63.(-124)-124.(-37)+(\(\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{11}\)).(-66)

                     Giúp mình với ạ! Mình cần gấp lắm 

II. Write the second sentence so that it has the same meaning as the given one:

1. Our children enjoy swimming in the sea in the summer.

 => Our children ……………………………………….........................................

2. It’s very easy to do that test.

=> I think …………………………………………………………………………

3. He's leaving now because he doesn't want to miss the coach

=> He doesn't want to miss the coach……………………………………………

4. Spending more time on computer games may lead to sore eyes.

=> They should ………………………………………………………………………

                                  Mấy bạn giúp mình với ạ