1+1/3+1/5...+1/97+1/99=(1+1/99) + (1/3+1/97) + (1/5+1/95)....+(1/49+1/51) 
= 100/1.99 + 100/3.97 + 100/5.95 +.....=100.(1/1.99 + 1/3.97 + 1/5.95 +.....) 
Mau so: 
1/1.99 + 1/3.97 +1/5.95....+1/95.5+ 1/97.3 +1/99.1=2/1.99 +2/3.97 +2/5.95+..... 
=2.(1/1.99 + 1/3.97 + 1/5.95 +.....) 
=>A=(100.(1/1.99 + 1/3.97 + 1/5.95 +.....)) : (2.(1/1.99 + 1/3.97 + 1/5.95 +.....))=50

chuẩn luôn , tích nha

Thanks nhìu  ^_^

yes , it is

she would like to eat mushroom

he was in USA last sunday

mong thầy hoặc cô có thể đánh dâu tick đúng =[

yes, i were

my favorite drink is milk

i often do my homework in the evening

they travel in my town by plane

mong thây hoặc cô có thể đánh dấu tick đúng =[

a] 31/40

b] 71/140

c] 773/150

d] 1/5

mong bạn tích dùm mình . Vì mình là người mới olm =/

84,3:3,5= 24,0[857142]

móng bạn tích dùm mình . Vì mình là người mới của olm

1 A

2 C

3 D

4 C

5 A

6 C

7 B

8 D

9 C

10 A

hello . My name is jack . Iam in class 4 A . I'm live in Phu Yen village . I'm study at Hoa My Dong primary school . My favorite subject is english . i have it in 2019 . Because it is good and it help me how to talk  speak english better

1 Iam playing football 

2 he likes taking photos

3 yes , they can

4 they are playing some games

5 yes , it is

1 Yes , she does

2 Yes, i'd like

3 i have maths , science , english and history

4 Yes , he is

5 we have works of art , colors and paintbrush

what happen to you =/