Mn lm giúp mik bài 9 vs ạ . Lm ơn mik đang rất cần
Ai lm giúp mik bài 2 vs ạ Mik đang cần gấp ạ Cảm ơn nhìu
Bài 2:
a: Xét ΔABC có
X là trung điểm của BC
Y là trung điểm của AB
Do đó: XY là đường trung bình
=>XY//AC và XY=AC/2=3,5(cm)
hay XZ//AC và XZ=AC
b: Xét tứ giác AZBX có
Y là trung điểm của AB
Y là trung điểm của ZX
Do đó: AZBX là hình bình hành
mà \(\widehat{AXB}=90^0\)
nên AZBX là hình chữ nhật
d: Xét tứ giác AZXC có
XZ//AC
XZ=AC
Do đó: AZXC là hình bình hành
GIÚP MIK LM BÀI NÀY VS Ạ . MIK ĐANG CẦN RẤT LÀ GẤP MONG BN THÔNG CẢM ! THANK YOU!
1B
2 bạn có chép đúng đề?
3D
4B
5A
6A
7A
8A
9B
10B
11C
12A
13C
14B
15A
16C
Ai lm giúp mik vs...Mik đang cần gấp ạ ( Cảm ơn )
\(a,\dfrac{11x}{2x-5}+\dfrac{x-30}{2x-5}=\dfrac{11x+x-30}{2x-5}=\dfrac{12x-30}{2x-5}=\dfrac{6\left(2x-5\right)}{2x-5}=6\)
\(b,\dfrac{3x^2-1}{2x}+\dfrac{x^2+1}{2x}=\dfrac{3x^2-1+x^2+1}{2x}=\dfrac{4x^2}{2x}=2x\)
\(c,\dfrac{3}{2x-5}+\dfrac{-2}{2x+5}+\dfrac{-20}{4x^2-25}=\dfrac{3\left(2x+5\right)}{\left(2x-5\right)\left(2x+5\right)}-\dfrac{2\left(2x-5\right)}{\left(2x-5\right)\left(2x+5\right)}-\dfrac{20}{\left(2x-5\right)\left(2x+5\right)}=\dfrac{6x+15-4x+10-20}{\left(2x-5\right)\left(2x+5\right)}=\dfrac{2x+5}{\left(2x-5\right)\left(2x+5\right)}=\dfrac{1}{2x-5}\)
\(d,\dfrac{x-2}{x-1}+\dfrac{x-3}{x+1}+\dfrac{4-2x^2}{x^2-1}=\dfrac{\left(x-2\right)\left(x+1\right)+\left(x-3\right)\left(x-1\right)+4-2x^2}{\left(x-1\right)\left(x+1\right)}=\dfrac{x^2-2x+x-2+x^2-3x-x+3+4-2x^2}{\left(x-1\right)\left(x+1\right)}=\dfrac{-5x+5}{\left(x-1\right)\left(x+1\right)}=\dfrac{-5\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}=\dfrac{-5}{x-1}\)
\(e,\dfrac{x+1}{x-1}+\dfrac{1-x}{x+1}+\dfrac{4}{x^2-1}=\dfrac{\left(x+1\right)^2}{\left(x-1\right)\left(x+1\right)}-\dfrac{\left(x-1\right)^2}{\left(x-1\right)\left(x+1\right)}+\dfrac{4}{\left(x-1\right)\left(x+1\right)}=\dfrac{x^2+2x+1-x^2+2x-1+4}{\left(x-1\right)\left(x+1\right)}=\dfrac{4x+4}{\left(x-1\right)\left(x+1\right)}=\dfrac{4\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}=\dfrac{4}{x-1}\)
mn lm giúp mik vs ạ.Mik đang cần gấp ạ.Nhanh ạ
Câu 6
a) Ta có: \(\widehat{A}=90^0\) ⇒a⊥c
a//b, a⊥c ⇒b⊥c
b) Ta lại có: M1+N1=1800(trong cùng phía)
1200+N1=1800
N1=1800-1200=600
ai lm giúp mik vs ....mik đang cần gấp ạ ( cho mik lời giải chi tiết nhé ..cảm ơn)
Giúp mik lm vs ập mik cảm ơn rất nhiều ạ
Bài 17:
1) \(3^2-x^2=\left(3-x\right)\left(3+x\right)\)
2) \(x^2-36=\left(x-6\right)\left(x+6\right)\)
3) \(y^2-1=\left(y-1\right)\left(y+1\right)\)
4) \(25-y^2=\left(5-y\right)\left(5+y\right)\)
5) \(9x^2-1=\left(3x-1\right)\left(3x+1\right)\)
6) \(\dfrac{1}{25}-4x^2=\left(\dfrac{1}{5}-2x\right)\left(\dfrac{1}{5}+2x\right)\)
7) \(9x^2-y^2=\left(3x-y\right)\left(3x+y\right)\)
8) \(x^2-4y^2=\left(x-2y\right)\left(x+2y\right)\)
Bài 18:
1) \(\left(x-5\right)\left(x+5\right)=x^2-25\)
2) \(\left(4-x\right)\left(4+x\right)=16-x^2\)
3) \(\left(x-\dfrac{2}{3}\right)\left(x+\dfrac{2}{3}\right)=x^2-\dfrac{4}{9}\)
4) \(\left(1+2x\right)\left(1-2x\right)=1-4x^2\)
5) \(-\left(2x+3\right)\left(3-2x\right)=\left(2x+3\right)\left(2x-3\right)=4x^2-9\)
6) \(-\left(5x-3\right)\left(3+5x\right)=\left(3-5x\right)\left(3+5x\right)=9-25x^2\)
7) \(-\left(3x-\dfrac{2}{5}\right)\left(3x+\dfrac{2}{5}\right)=-\left(9x^2-\dfrac{4}{25}\right)=\dfrac{4}{25}-9x^2\)
8) \(-\left(2x-\dfrac{2}{3}\right)\left(2x+\dfrac{2}{3}\right)=-\left(4x^2-\dfrac{4}{9}\right)=\dfrac{4}{9}-4x^2\)
1)\(\left(x+2\right)^2\)
2)\(\left(x+3\right)^2\)
3)\(\left(2x+1\right)^2\)
4)\(\left(3+2x\right)^2\)
5)\(\left(x-1\right)^2\)
6)\(\left(x-4\right)^2\)
7)\(\left(6-x\right)^2\)
8)\(\left(2x-3y\right)^2\)
9)\(\left(3x-1\right)^2\)
2.what should you do to protect the environment as a student?
Ai lm giúp mik vs ạ...Mik đang cần gấp
Cảm ơn nhìu ạ
You can refer this one:
Recycle/Reuse Your Books. ...
Ditch the Paper. ...
Buy a Water Bottle. ...
Turn Off Your Phone. ...
Recycle. ...
Avoid Public Transport When Possible. ...
Save Water. ...
Save Electricity.
Viết chủ đề Pollution nêu nguyên nhân kết quả và cách phòng chống
Ai lm giúp mik vs ạ...Mik đang cần gấp ạ...Cảm ơn nhìu ạ
Tham khảo :
The air pollution is so dangerous for people in my area. There are two problems about causes and effects. About causes, firstly, many vehicles discharge dust and smoke into the environment. Besides, factories dump waste poison out. Finally, people littering anywhere, such as parks, beaches, schools and even on the way. About effects, firstly, people can suffer from many respiratory diseases. Second, people can't live long because of lack of oxygen. And last, it will destroy the ozone layer and make it easier for the Sun rays to penetrate the Earth. In short, I think we should protect the air's purity before it's too late.
Which country do you want to visit if you have a chance ?
Ai lm giúp mik vs ạ..Mik đang cần gấp ạ
Cảm ơn nhìu ạ
I'd like to visit New York in United States of America OR London in United Kingdom