Giúp mik đê câu 5 á ahuhu😭😭😭😭😭
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Yes
5 hours
Because some say that there is a lot of violence on TV today, the programs are terrible and people don't get any exercise because they only sit and watch TV
It brings news from around the world, help you learn many useful things, especially children
We learn about life in other countries
1. Yes, it is.
2. Americans watch TV 5 hours a day.
3. Some say that there is a lot of violence on TV today, the programs are terrible and people don't get any exercise because they only sit and watch TV.
4. It brings news from around the world.
5. You can learn many new things, about life in other countries and it also helps people relax after a long day of hard work.
a)Xét ΔAKB và ΔCAB có:
\(\widehat{AKB}=\widehat{BAC}=90^o\left(gt\right)\)
\(\widehat{C}chung\)
⇒ΔAKB ~ ΔCAB(g-g)
b)Xét ΔABC có:OB=OC(O là trung điểm BC);BI=AI(I là trung điểm AB)
⇒OI là đường TB ΔABC(đ/n)
⇒OI//AC(t/c)
Mà AC⊥AB(gt) ⇒OI⊥AB(t/c)
Xét ΔBOI và ΔBAK có:
\(\widehat{BIO}=\widehat{BKA}=90^o\)
\(\widehat{B}\) chung
⇒ΔBOI ~ ΔBAK(g-g)
⇒\(\dfrac{BI}{BK}=\dfrac{BO}{BA}\Rightarrow BI.BA=BK.BO\)(đpcm)
c) C=(151515/161616 + 17^9/17^10)-(1500/1600 - 1616/1717)
=(15/16 + 1/17)-(15/16 - 16/17)
= 15/16 ( 1/17 + 16/17)
=15/16 . 1 = 15/16