Gọi vận tốc của xe máy là x(km/h)

Đk: x>0

Vận tốc của xe đạp là:x−20(km/h)

Quãng đường xe máy đi được là:3x(km)

Quãng đường xe đạp đi được là:5(x−20)(km)

Vì quãng đường xe máy đi được bằng quãng đường xe đạp nên ta có phương trình

3x=5(x−20)⇔3x=5x−100⇔3x−5x=−100⇔−2x=−100⇔x=50(tmđk)

Vậy vận tốc xe máy là  50km/h

Vận tốc xe đạp là:50−20=30(km/h)

1. joined 2. are parading 3. marks 4. was held 5. is awarded 6. will take place 7. has been 8. Have you ever attended 9. to write 10. ta1. joined 2. are parading 3. marks 4. was held 5. is awarded 6. will take place 7. has been 8. Have you ever attended 9. to write 10. taking1. joined 2. are parading 3. marks 4. was held 5. is awarded 6. will take place 7. has been 8. Have you ever attended 9. to write 10. taking

1,Our parents (live)....live.....in HP.They (live)..have lived....there for our 14 years

2,I want (see).to see......the doctor right now

3,My aunt(not be).....hasn't been.......out of her house since she (buy)..bought..a TV?
4,Mary hasn't (write)...written.......the Test yet

5,My mother has just (go)..gone.....to the market

6,They have already (eat)..eaten...durian

1. She drinks a lot of mineral waters in a day.

waters => water

2. you should'n run or walk careless around the lake.

careless => carelessly
3. Mary told me that her aunt cutted her hải yesterday.

cutted => cut

1. Why Long ( not/ want) didn't want to play soccer last Sunday?

2. She doesn't know Hung's sister. She (never/meet) has never met her.

3. When did you (start) started school? - When I (be) was six.

4. He usually wears sandals but when I last saw him he wore (wear) boots.

5.The class was begining (begin) before we came yesterday.

6. Tom have just ( just) go out at home when I arrived.

7. Where did you get after my parents leave(leave)?

8. His father (eat) ate while his mother (sew) sew a cushion last night.

9. I was happy to see her again after such a long time. I haven't seen ( not see) her for years.

10. Was Mary at home when you phone ?

   No. She just has left (just leave).