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Quoc Tran Anh Le Coodinator
14/09/2018 at 07:07
When written in base 7, the number is a.7^{2} + b.7 + c
When written in base 6, the number is (a+1).6^{2} + (b+1).6 + c +1
We get: a.7^{2} + b.7 + c = (a+1).6^{2} + (b+1).6 + c +1, it implies 13a + b = 43.
This yields a = 3, b = 4.
When written in base 10, the largest number possible: 3.7^{2} + 4.7 + 9 = 184
Quoc Tran Anh Le selected this answer.
Quoc Tran Anh Le Coodinator
14/09/2018 at 07:06
Alone 14/09/2018 at 16:17
Because \(\dfrac{12x}{25}\) is a square number but 12=2^{2}.3
So \(x⋮25\) and x smallest so x=3.25=75
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Huỳnh Anh Phương
11/09/2018 at 13:46
Huy Toàn 8A (TL) 15/09/2018 at 06:19
Let x, y be the length and width of the rectangle:
We have :
\(\left\{{}\begin{matrix}xy=8\\x=2y\end{matrix}\right.=>\left\{{}\begin{matrix}2y^2=8\\x=2y\end{matrix}\right.< =>\left\{{}\begin{matrix}y=2\left(cm\right)\\x=4\left(cm\right)\end{matrix}\right.\)
So the rectangle width is 2cm
Huỳnh Anh Phương selected this answer. 
Dương Đào Xuân 03/10/2018 at 14:00
OÁCH SOẠCH
Quoc Tran Anh Le Coodinator
09/09/2018 at 09:55Quoc Tran Anh Le Coodinator
09/09/2018 at 09:54Quoc Tran Anh Le Coodinator
09/09/2018 at 09:53Quoc Tran Anh Le Coodinator
09/09/2018 at 09:52Quoc Tran Anh Le Coodinator
09/09/2018 at 09:51Quoc Tran Anh Le Coodinator
09/09/2018 at 09:51Huỳnh Anh Phương
03/09/2018 at 12:52
Huy Toàn 8A (TL) 03/09/2018 at 13:55
We have a sequence of numbers :
\(12;21;30;39;48;B;66;...\)
The numbers separated by 9 units
=> B = 48 + 9 = 57
So B = 57
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mylifepathinheaven130609 19/09/2018 at 14:53
hmmmmmmmmmmmmmm......
i dunno
hi im psycho i knifes and i'm 9 years old

Bùi Vũ Hoàng Linh 21/01/2019 at 12:47
B là 57