bài 1: CM a+c=2b và 2bd=c (b+d)

(b,d khác 0) thì a/b=c/d

bài 2: cho 2/a=1/b+1/c (a,b,c khác 0)

CM: b/c=b-a/a-c

change the sentences inton passive

1.in USA, people will throw away millions of cars

2.he hasn't sent the present to her yet

3.why doesn't the cat eat all the milk?

4.will they send application before december 30th?

5.how did people learn english?

6. does your country export rice?

7. how often does she clean the room?

change the sentences inton passive

1.in USA, people will throw away millions of cars

2.he hasn't sent the present to her yet

3.why doesn't the cat eat all the milk?

4.will they send application before december 30th?

5.how did people learn english?

6. does your country export rice?

7. how often does she clean the room?