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Nguyễn Mạnh Hùng 19/06/2018 at 08:50\(\left\{{}\begin{matrix}2a+b=19\left(1\right)\\2c+d=37\left(2\right)\end{matrix}\right.\)
Put (1) + (2) we have:
\(2a+b+2c+d=56\)
\(\Rightarrow2a+2c=32\) (because b + d = 24 )
\(\Rightarrow a+c=16\)
So a + b + c + d = 24 + 16 = 40
Lê Quốc Trần Anh selected this answer.
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Tôn Thất Khắc Trịnh 23/07/2018 at 16:04I won't take credit for this solution, as it goes to this website: https://www.cut-the-knot.org/proofs/LinesDividePlane.shtml
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Applying 2016 to the formula, we'll get 2033137 regions, which has the sum of digit be 19 -
Mr Puppy 24/07/2018 at 01:44
Thank you!!!!! :D
Quoc Tran Anh Le Coordinator
06/08/2018 at 02:37
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Huy Toàn 8A (TL) 06/08/2018 at 03:24We have:
\(\dfrac{10^{11}+10^{10}}{10^{10}}\)
\(< =>\dfrac{10^{10}\left(10+1\right)}{10^{10}}\)
= 11
The answer is : 11
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We have : 7*(x*4) = 7*(3x - 20) = 21 - 5(3x - 20) = 121 - 15x
So 121 - 15x = 1 => 15x = 120 => x = 8
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Nguyễn Nhật Minh 30/05/2017 at 12:09There are 24 hours in a day.
So, a quarter of a day = 24 \(\times\dfrac{1}{4}\) = 6 hours.
Thus, a third of 6 hours = 6 \(\times\dfrac{1}{3}\) = 2 hours.
Thereupon (also means Thus), a half of 2 hours = 2 \(\times\dfrac{1}{2}\) = 1 hour.
Therefore, a half of a third of a quarter of a day is 1 hour. So we choose C.
Answer. C
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Dương Minh Hiếu 02/06/2017 at 10:30answer c
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The total money of 3 person is: \(53.3=159\left(million\right)\)
The taxes of 1 person is: \(\left(234-159\right):3=25\left(millions\right)\)
The total of the money of 1 person: \(25+53=78\left(million\right)\)
The percentage of the tax of 1 person is: \(25:78\simeq0,3205\simeq32,05\%\)
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Let a,b,c sequence is length, width and height of this rectangular prism. We have:
\(\dfrac{a}{3}=\dfrac{b}{2}=c\); abc = 48
Let \(\dfrac{a}{3}=\dfrac{b}{2}=c=k\Rightarrow\left\{{}\begin{matrix}a=3k\\b=2k\\c=k\end{matrix}\right.\)
=> abc = 3k.2k.k = 6k3 = 48
=> k3 = 8 => k = 2
=> a = 2.3 = 6
So the length of this prism is 6in = 15,24cm
Lê Quốc Trần Anh selected this answer.
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Because the word ALGEBRA has 6 different letters so we have 6 slips of paper for this word.
So the probability is: \(\dfrac{6}{26\left(26-1\right)}=\dfrac{6}{650}=\dfrac{3}{325}\)
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