i am supposed to get 7-9 hour of sleep per night but i get like 5 how do i sleep beter?

Answer 1

You aren't providing enough information to really answer this question. Are you not getting enough sleep because you: have insomnia
burn the candle at both ends (by choice)
just get sidetracked and don't go to bed
etc?

If you can't sleep because you are burning the candle or getting sidetracked, then you just have to make a real effort to set a bed time and stick to it.

If you simply can't sleep, follow the strategies for coping with insomnia:
avoid or limit caffeine, nicotine, and alcohol, especially in the evening.
make sure none of your medications are affecting your sleep
go to bed and get up at the same time EVERY day
save the bed for sleeping and sex only...no tv
exercise daily at least 4 hours before bedtime
limit bedtime to 8 hours
do not nap
relax in the evenings...don't do anything stimulating
eat meals at regular times
try to avoid a bedtime snack
when in bed, concentrate on relaxing
get lots of sunshine
keep your bedroom quiet, dark, and cool
try a sleep mask
avoid beverages at night
try using white noise

It might help to try and keep a sleep diary so that you can document your sleep issues. If it is insomnia and these strategies don't help, see a doctor.