33 the meeting was attended by all students
35 i will be taken to HCM city next week by my father
36 fruit have to be picked very early in the morning by us 
37 sandwiches are usually brought him at lunch by his wife
38 we have been given a lots of advantages by the 21th century
39 that questions can be answered by no one 
40 all of my E books have been taken away by someone
 

30 we were

27 a supermarket are being built on our street by the worker
28 jeans are sold all over the world by them
29 a new library is going to be built in the area by people
30 we was made laugh a lot by the clown
31 a meeting will  be held next week
32 bananas are exported to Europe every year by people

bạn ơi giải thích đáp án với ạ 

AH/BC=3/10 nếu trên hình k thấy rõ nha

Có a3-3ab2=10=>(a3-3ab2)2=100(1)

Có b3-3a2b=5=>(b3-3a2b)2=25(2)

Cộng (1) và (2)

=>(a3-3ab2)2+(b3-3a2b)2=100+25

<=>a6-6a4b2+9a2b4+b6-6a2b4+9a2b4=125

<=>a6+3a2b4+3a4b2+b6=125

<=>(a2+b2)3=125

<=>a2+b2=5

vậy a2+b2=5