# All Questions

##### Summer Clouds moderators

03/11/2017 at 08:55-
Denote \(\dfrac{x}{3}=\dfrac{y}{4}=k\), then x = 3k ; y = 4k

We have : \(3k.4k=108\Leftrightarrow12k^2=108\Leftrightarrow k^2=9\Leftrightarrow k=\pm3\)

So, (x ; y) = (9 ; 12) ; (-9 ; -12)

Selected by MathYouLike -
Nguyễn Đặng Hoàng Phúc 13/11/2017 at 21:08
We have:\(\dfrac{x}{3}=\dfrac{y}{4}\Rightarrow\dfrac{xy}{12}=\dfrac{x^2}{9}=\dfrac{108}{12}=9\Rightarrow x^2=81\)

\(\Rightarrow x=\pm9\)\(\Rightarrow y=\pm12\)

So \(\left(x,y\right)\in\left\{\left(-9,-12\right);\left(9,12\right)\right\}\) satisfy problem

##### Lê Quốc Trần Anh Coodinator

11 hour ago (02:22)##### Lê Quốc Trần Anh Coodinator

11 hour ago (02:22)##### Lê Quốc Trần Anh Coodinator

11 hour ago (02:21)##### Lê Quốc Trần Anh Coodinator

11 hour ago (02:21)##### Lê Quốc Trần Anh Coodinator

11 hour ago (02:20)##### Lê Quốc Trần Anh Coodinator

11 hour ago (02:19)##### Lê Quốc Trần Anh Coodinator

11 hour ago (02:19)##### Lê Quốc Trần Anh Coodinator

11 hour ago (02:18)##### Nguyễn Thị Ý Nhi

11 hour ago (01:53)-
jimin bts cute 11 hour ago (02:09)
yes, i know

i jimin

and jungkook

Nguyễn Thị Ý Nhi selected this answer.

##### Nguyễn Thị Ý Nhi

11 hour ago (01:51)-
jimin bts cute 11 hour ago (01:59)
a, \(126+\left(-20\right)+2004+\left(-106\right)\)

\(=126+\left(-20\right)+2004+\left(-106\right)\)

\(=106+2004+\left(-106\right)\)

\(=106+\left(-106\right)+2004\)

\(=0+2004\)

\(=2004\)

Nguyễn Thị Ý Nhi selected this answer.

##### Nguyễn Thị Ý Nhi

11 hour ago (01:49)-
jimin bts cute 11 hour ago (02:06)
a, - 4< x < 3

\(x\in\left\{-3;-2;-1;0;1;2\right\}\)

\(x=\left(-3\right)+\left[\left(-2\right)+2\right]+\left[\left(-1+1\right)\right]+0\)

\(x=\left(-3\right)+0+0+0\)

\(x=\left(-3\right)\)

b, \(-5< x< 5\)

\(x\in\left\{-4;-3;-2;-1;0;1;2;3;4\right\}\)

\(x=\left[\left(-4\right)+4\right]+\left[\left(-3\right)+3\right]+\left[\left(-2\right)+2\right]+\left[\left(-1\right)+1\right]+0\)

\(x=0+0+0+0+0\)

Nguyễn Thị Ý Nhi selected this answer.

##### Huỳnh Anh Phương

Yesterday at 11:07##### Lê Quốc Trần Anh Coodinator

Yesterday at 03:14##### Lê Quốc Trần Anh Coodinator

Yesterday at 03:14##### Lê Quốc Trần Anh Coodinator

Yesterday at 03:14##### Lê Quốc Trần Anh Coodinator

Yesterday at 03:13##### Lê Quốc Trần Anh Coodinator

Yesterday at 03:13##### Nguyễn Thị Ý Nhi

Yesterday at 01:43-
jimin bts cute Yesterday at 01:46
\(26+\left(-6\right)=20\)

\(\left(-73\right)+0=-73\)

study well !^_^

Nguyễn Thị Ý Nhi selected this answer.

##### Nguyễn Thành Long

27/05/2018 at 13:24-
We have: \(\dfrac{\dfrac{1}{2}-\dfrac{1}{3}}{\dfrac{1}{3}-\dfrac{1}{4}}\times\dfrac{\dfrac{1}{4}-\dfrac{1}{5}}{\dfrac{1}{5}-\dfrac{1}{6}}\times...\times\dfrac{\dfrac{1}{2006}-\dfrac{1}{2007}}{\dfrac{1}{2007}-\dfrac{1}{2008}}=\dfrac{\dfrac{1}{2\cdot3}}{\dfrac{1}{3\cdot4}}\times\dfrac{\dfrac{1}{4\cdot5}}{\dfrac{1}{5\cdot6}}\times...\times\dfrac{\dfrac{1}{2006\cdot2007}}{\dfrac{1}{2007\cdot2008}}\)

\(=\dfrac{3\cdot4}{2\cdot3}\times\dfrac{5\cdot6}{4\cdot5}\times...\times\dfrac{2007\cdot2008}{2006\cdot2007}=\dfrac{2008}{2}=1004\)