20:

1: Xét ΔACD và ΔABE có

AC=AB

góc A chung

AD=AE

=>ΔACD=ΔABE

2: ΔABE=ΔACD

=>góc ABE=góc ACD

=>góc IBD=góc ICE

3: Xét ΔIBD và ΔICE có

góc IBD=góc ICE
BD=CE
góc IDB=góc IEC
=>ΔIBD=ΔICE

4: ΔIBD=ΔICE

=>IB=IC; ID=IE

=>ΔIBC cân tại I; ΔIDE cân tại I

không có câu hỏi sao trả lời

Is this a test?

test

bn làm đề KT hay thi hay bt hay đề ôn tập thì tự lm nhé

Câu 5:

a. $|x+\frac{4}{5}|-\frac{1}{7}=0$

$|x+\frac{4}{5}|=\frac{1}{7}$

$\Rightarrow x+\frac{4}{5}=\pm \frac{1}{7}$

$\Rightarrow x=\frac{-23}{35}$ hoặc $x=\frac{-33}{35}$

v.

$2x+5-(x-7)=18$

$2x+5-x+7=18$

$x+12=18$

$x=6$

c.

$2(x+1)+4^2=2^4$
$2(x+1)+16=16$

$2(x+1)=0$

$x+1=0$

$x=-1$

d.

$\frac{x-3}{x+5}=\frac{5}{7}$

$\Rightarrow 7(x-3)=5(x+5)$

$\Rightarrow 7x-21=5x+25$

$\Rightarrow 2x=46$

$\Rightarrow x=23$

Câu 5:

\(a,\left|x+\dfrac{4}{5}\right|-\dfrac{1}{7}=0\\ \Leftrightarrow\left|x+\dfrac{4}{5}\right|=\dfrac{1}{7}\\ \Leftrightarrow\left[{}\begin{matrix}x+\dfrac{4}{5}=\dfrac{1}{7}\\x+\dfrac{4}{5}=-\dfrac{1}{7}\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{7}-\dfrac{4}{5}\\x=-\dfrac{1}{7}-\dfrac{4}{5}\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{23}{35}\\x=-\dfrac{33}{35}\end{matrix}\right.\\ b,2x+5-\left(x-7\right)=18\\ \Leftrightarrow2x-x=18-5-7\\ \Leftrightarrow x=6\\ c,2\left(x+1\right)+4^2=2^4\\ \Leftrightarrow2\left(x+1\right)=2^4-4^2=16-16\\ \Leftrightarrow2\left(x+1\right)=0\\ \Rightarrow x+1=0\\ \Leftrightarrow x=0-1=-1\\ d,\dfrac{x-3}{x+5}=\dfrac{5}{7}\left(x\ne-5\right)\\ \Leftrightarrow7\left(x-3\right)=5\left(x+5\right)\\ \Leftrightarrow7x-21=5x+25\\ \Leftrightarrow7x-5x=25+21\\ \Leftrightarrow2x=46\\ \Leftrightarrow x=23\)

Câu 6:

b. Trung bình cộng các điểm: 

$\overline{x}=\frac{5.1+6.3+7.4+8.5+9.4+10.3}{20}=7,85$

a) \(p=d\cdot h=150\cdot10^{-4}\cdot10000=150Pa\)

b) \(F_A=d\cdot V=10000\cdot400\cdot10^{-6}=4N\)

*Theo mình là 
D.Cung cấp chất dinh dưỡng cho cây trồng
_______
𝗖𝗵𝘂́𝗰 𝗯𝗮̣𝗻 𝗱𝘁𝗵𝘄 𝗵𝗼̣𝗰 𝘁𝗼̂́𝘁( ◍•㉦•◍ )
🥺🍊

Mình giúp câu nào mình biết thôi nhé:v

1.D     3.B      4.C   5.A    6.Do chứa nhiều hạt sét

1. Yes,it is.

2. They watch TV about 5 hours (35(hours Americans watch TV for a week):7)

3. Because they think 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. We learn many useful things.