Giúp mik
mik cần gấp
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máy bn ơi giúp mik vs mik đag cần gấp
cảm ơn
\(\dfrac{2019x}{xy+2019x+2019}+\dfrac{y}{yz+y+2019}+\dfrac{z}{xz+z+1}\)
\(=\dfrac{2019xz}{xyz+2019xz+2019z}+\dfrac{xz.y}{xz.yz+xz.y+2019xz}+\dfrac{z}{xz+z+1}\)
\(=\dfrac{2019xz}{2019+2019xz+2019z}+\dfrac{2019}{2019z+2019+2019xz}+\dfrac{z}{xz+z+1}\)
\(=\dfrac{xz}{1+xz+z}+\dfrac{1}{z+1+xz}+\dfrac{z}{xz+z+1}\)
\(=\dfrac{xz+z+1}{xz+z+1}=1\)
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giúp mk bài 2 nhanh nhé mk đang cần gấp
cảm ơn
Bài 2:
1) \(x^2-4=x^2-2^2=\left(x-2\right)\left(x+2\right)\)
2) \(1-4x^2=1^2-\left(2x\right)^2=\left(1-2x\right)\left(1+2x\right)\)
3) \(4x^2-9=\left(2x\right)^2-3^2=\left(2x+3\right)\left(2x-3\right)\)
4) \(9-25x^2=3^2-\left(5x\right)^2=\left(3-5x\right)\left(3+5x\right)\)
5) \(4x^2-25=\left(2x\right)^2-5^2=\left(2x+5\right)\left(2x-5\right)\)
6) \(9x^2-36=\left(3x\right)^2-6^2=\left(3x-6\right)\left(3x+6\right)\)
7) \(\left(3x\right)^2-y^2=\left(3x-y\right)\left(3x+y\right)\)
8) \(x^2-\left(2y\right)^2=\left(x-2y\right)\left(x+2y\right)\)
9) \(\left(2x\right)^2-y^2=\left(2x-y\right)\left(2x+y\right)\)
10) \(\left(3x\right)^2-9y^4=\left(3x\right)^2-\left(3y^2\right)^2=\left(3x-3y^2\right)\left(3x+3y^2\right)\)
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Bài 2:
21) \(\left(\dfrac{x}{3}-\dfrac{y}{4}\right)\left(\dfrac{x}{3}+\dfrac{y}{4}\right)=\left(\dfrac{x}{3}\right)^2-\left(\dfrac{y}{4}\right)^2=\dfrac{x^2}{9}-\dfrac{y^2}{16}\)
22) \(\left(\dfrac{x}{y}-\dfrac{2}{3}\right)\left(\dfrac{x}{y}+\dfrac{2}{3}\right)=\left(\dfrac{x}{y}\right)^2-\left(\dfrac{2}{3}\right)^2=\dfrac{x^2}{y^2}-\dfrac{4}{9}\)
23) \(\left(\dfrac{x}{2}+\dfrac{y}{3}\right)\left(\dfrac{x}{2}-\dfrac{y}{3}\right)=\left(\dfrac{x}{2}\right)^2-\left(\dfrac{y}{3}\right)^2=\dfrac{x^2}{4}-\dfrac{y^2}{9}\)
24) \(\left(2x-\dfrac{2}{3}\right)\left(\dfrac{2}{3}+2x\right)=\left(2x-\dfrac{2}{3}\right)\left(2x+\dfrac{2}{3}\right)=\left(2x\right)^2-\left(\dfrac{2}{3}\right)^2=4x^2-\dfrac{4}{9}\)
25) \(\left(2x+\dfrac{3}{5}\right)\left(\dfrac{3}{5}-2x\right)=\left(\dfrac{3}{5}+2x\right)\left(\dfrac{3}{5}-2x\right)=\left(\dfrac{3}{5}\right)^2-\left(2x\right)^2=\dfrac{9}{25}-4x^2\)
26) \(\left(\dfrac{1}{2}x-\dfrac{4}{3}\right)\left(\dfrac{4}{3}+\dfrac{1}{2}x\right)=\left(\dfrac{1}{2}x-\dfrac{4}{3}\right)\left(\dfrac{1}{2}x+\dfrac{4}{3}\right)=\left(\dfrac{1}{2}x\right)^2-\left(\dfrac{4}{3}\right)^2=\dfrac{1}{4}x^2-\dfrac{16}{9}\)
27) \(\left(\dfrac{2}{3}x^2-\dfrac{y}{2}\right)\left(\dfrac{2}{3}x^2+\dfrac{y}{2}\right)=\left(\dfrac{2}{3}x^2\right)^2-\left(\dfrac{y}{2}\right)^2=\dfrac{4}{9}x^4-\dfrac{y^2}{4}\)
28) \(\left(3x-y^2\right)\left(3x+y^2\right)=\left(3x\right)^2-\left(y^2\right)^2=9x^2-y^4\)
29) \(\left(x^2-2y\right)\left(x^2+2y\right)=\left(x^2\right)^2-\left(2y\right)^2=x^4-4y^2\)
30) \(\left(x^2-y^2\right)\left(x^2+y^2\right)=\left(x^2\right)^2-\left(y^2\right)^2=x^4-y^4\)
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Bài `3`
\(1,\left(2x+1\right)^2+\left(2x-1\right)^2\\ \left[\left(2x\right)^2+4x+1^2\right]+\left[\left(2x\right)^2-4x+1^2\right]\\ =4x^2+4x+1+4x^2-4x+1\\ =8x^2+2\)
\(2,-\left(x+1\right)^2-\left(x-1\right)^2\\ =-\left(x^2+2x+1^2\right)-\left(x^2-2x+1\right)\\ =-x^2-2x-1-x^2+2x-1\\ =-2x^2-2\)
\(3,\left(x+2y\right)^2-\left(x-2y\right)^2\\ =\left[\left(x+2y\right)+\left(x-2y\right)\right]\left[\left(x+2y\right)-\left(x-2y\right)\right]\\ =\left(x+2y+x-2y\right)\left(x+2y-x+2y\right)\\ =2x.4y=8xy\)
\(4,\left(3x+y\right)^2+\left(x-y\right)^2\\ =\left[\left(3x\right)^2+6xy+y^2\right]+\left[\left(x^2-2xy+y^2\right)\right]\\ =6x^2+6xy+y^2+x^2-2xy+y^2\\ =7x^2+4xy+2y^2\)
\(5,-\left(x+5\right)^2-\left(x-3\right)^2\\ =-\left(x^2+10x+5^2\right)-\left(x^2-6x+3^2\right)\\ =-x^2-10x-25-x^2+6x-9\\ =-2x^2+16x-34\)
\(6,\left(3x-2\right)^2-\left(3x-1\right)^2\\ =\left[\left(3x-2\right)+\left(3x-1\right)\right]\left[\left(3x-2\right)-\left(3x-1\right)\right]\\ =\left(3x-2+3x-1\right)\left(3x-2-3x+1\right)\\ =\left(6x-3\right)\left(-1\right)=-6x+3\)
`@ Kidd`
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| x + 1 | = | -3x = 2 |
mn giúp e với ạ, e đang cần gấp
cảm ơn ạ
Tìm số nguyên x,biết
-12-|13-x|=-21
Giúp mình với ,mình cần gấp
Cảm ơn
\(\Leftrightarrow\left|13-x\right|=9\Leftrightarrow\left[{}\begin{matrix}13-x=9\\x-13=9\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=22\end{matrix}\right.\)
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=>|13-x|=9
\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=22\end{matrix}\right.\)
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nêu cách tách riêng hỗn hợp:bột,đá vôi,muối ăn
các bạn giúp mk với ạ mk đg cần gấp
cảm ơn <3
GIÚP Ạ, CẦN GẤPCẢM ƠN NHIỀUCâu 1: Mr. Johnson and his daughter do not always understand each other.A.older B. the oldestC.eldest D. the eldestCâu 2 : Bill Gates is one of the________________ people in the world.A.rich B. richerC.richest ...
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GIÚP Ạ, CẦN GẤP
CẢM ƠN NHIỀU
Câu 1: Mr. Johnson and his daughter do not always understand each other.
A.older B. the oldest
C.eldest D. the eldest
Câu 2 : Bill Gates is one of the________________ people in the world.
A.rich B. richer
C.richest D. richly
Câu 3 : The Dead Sea is the_____________ place in the world.
A. low B. lowest
C. lower D. no answer is correct
Câu 6 : The English test was___________ than I expected.
A.more difficult B. difficult
C.the inost difficult D. no answer is correct
Câu 7 : I have a headache. I feel __________than yesterday.
A.badly B. bader
C.worse D. worst
Câu 8 : They hardly believe that the apartment which costs them $ 4,000 is
A.so small B. such little
C.so little D. such small
Câu 9 : What I would do is to go
A.really quietly somewhere B. somewhere quietly really
C.really quiet somewhere D. somewhere really quiet
Câu 10 : The price was very reasonable; I would gladly have paid he asked.
A.three times much as B. three times as many as
C.as three times much as D. three times as much as
Câu 11 : The trousers are , but Tom does not care a bit.
A.too a little small B. a little too small
C.a too little small D. a small too little
Câu 12 : Kasia is taking her tour of the shops in search of bargains.
A.daily B. day
C.day time D. night
Câu 13 : I was worried very much because I’ll miss my flight if the bus arrives
A. lately B. late
C.latter D. more later
Câu 14 : The noise outside was his speech was hardly audible.
A.too irritating that B. so irritated that
C.so irritating that D. so irritating enough that
Câu 15 : The harder the shrub is to grow,
A. the more higher price it B. the higher price it is
C. the higher the price is D. the higher is the price
Câu 16 : The photographs of Mars taken by satellite are taken from the earth.
A.clearest than those B. clearer than that
C.much clear than those D. much clearer than those
Câu 17 : anywhere in the United States costs less than a dollar when you dial it yourself.
A.Three-minute call B. A three-minutes call
C.A three-minute call D. A three-minutes-call
Câu 18: We arrived Professor Baker had already called the roll.
A.so lately that B. as late that
C.so later that D. so late that
Câu 19 : Her little car isn’t to seat more than two people comfortably.
A.big enough B. enough big
C.so big enough D. big as enough
Câu 20 : His score on the exam was to qualify him for a graduate program.
A.too good B. well enough
C.as high as D. good enough
Câu 21 : There are that I can’t finish them.
A.so long assignments B. such long assignments
C.long assignments D. so very long assignments
Câu 22: Your application will be considered your file is completed.
A.as quickly as B. as soon as
C.as fast as D. as early as
Câu 23 : A new shopping center on the north side will have
A.five hundred more than shops B. as more than five hundred shops
C.five hundred shops more than D. more than five hundred shops
Câu 24 :The more you study during the semester, you have to study the week before exams.
A.the less B. the lesser
C.less D. the little
Câu 25 : The salary of a taxi driver is much higher ______________
A.in comparison with the salary of a teacher B. than a teacher
C.than that of a teacher D. to compare as a teacher
Câu 26 : When electricity was first invented, people refused to believe such a thing
A.impossible B. possibly
C.possible D. impossibly
Câu 27 : The reason why so many people sit before the television tonight is that there will be a show.
A.living B. live
C.alive D. lived
Câu 28 : When the three boys met one another, they found they looked very much . Then they knew they were triplet.
A.like B. alike C. likely D. liked
Câu 29 : If you live in Wuhan one day and in Shenyang the next, you the change in temperature.
A.are certainly to feel B. certainly feel
C.are to feel certainly D. are certain to feel
Câu 30 : People will be able to fly from one planet to another in
A.little nasty arrow-shaped tubes B. nasty little arrow-shaped tubes
C.arrow-shaped little nasty tubes D. arrow-shaped little nasty tubes
1 C
2 C
3 B
6 A
7 C
8 C
9 C
10 D
11 B
12 A
13B
14 C
15 C
16 B
17 C
18 D
19 A
20 D
21 D
22 B
23 C
24 A
25 C
26 C
27 B
28 B
29 B
30 D
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1.what do you think about the environment in your town?
Ai lm giúp mik vs ạ
Mik đang cần gấp
Cảm ơn nhìu ạ
1.what do you think about the environment in your town?
In my hometown , people are not aware of environmental protection, there are still many people who are unaware and throw their garbage out, besides, there are still people who pick up trash and throw it in the right place.
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Every day on the news reports, the news is everywhere, saying phrases like melting ice, global warming, acid rain, global climate change or adding new lands to become industrial landfills. All are consequences of environmental pollution.
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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.
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| những điều em nhận và biết | những điều em còn băn khoăn |
về bài chị gọi em bằng tên
mn người trả lời giúp đang cần gấp
cảm ơn!!!!
Làm tròn các số sau giúp ạ, làm tròn sao cho còn 1 chữ số ở bên phải dấu phẩy:
11,888888888888888
99,99999999999
30,66666666666666
48,652154654
98,5454545454
69,874444
69,69
96,969696
Giúp ạ cần raatstttttttttt gấp
Cảm ơn.
11,9
100,0
30,7
48,7
98,6
69,9
69,7
97,0
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11,9
100,0
30,7
48,7
98,5
69,9
69,7
97,0
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