how much do these rackets cost?

1.Huyen walks to school every morning .

Huyen goes to school every morning.

2.Does your school have over eight hundred pupils?

Are there over eight hundred pupils in your school?

3.That motorbike belong to Mr.Trung.

That is Mr.Trung's motorbike.

4.My brother is driving to work now.

My brother is travling to work by car now.

5.This exercise is very difficult and I can't do it.

This exercise is too difficult for me to do

goi hai so can tim la a,b Ta co a:1/4=b:1/5=>ax4=bx5=>(b+68)x4=bx5=>4b+272=5b=>b=272=>a=272+68=340

đẹp lắm cj ạ! cj thật có tài vẽ tranh