DE đâu ra?

`3/7x = -1/3 : 2/9`

`=> 3/7x = -1/3 . 9/2`

`=> 3/7 x = -3/2`

`=> x = -3/2 . 7/3`

`=> x = -7/2`

`A = 2 + 2^2 + 2^3 + .... +` \(2^{2016}\)

`2A = 2^2 + 2^3 + 2^4 + .... +` \(2^{2017}\)

`2A - A =` \(2^{2017}-2\)

`A =` \(2^{2017}-2\)

Do `M` là trung điểm `AB` nên

`MA = MB =` \(\dfrac{1}{2}\) `AB = `\(\dfrac{1}{2}\) `. 9 = 4,5`

`5/13 + 2/7 + 8/13 - 3/14`

`= (5/13 + 8/13) + (2/7 - 3/14)`

`= 13/13 + 1/14`

`= 1 + 1/14 `

`= 15/14`

`x + (-3/7) = -7/2 + (-3/7)`

`=> x + 7/2 =  (-3/7) -  (-3/7)`

`=> x + 7/2 = 0`

`=> x = -7/2`

`23/14 = 2 - 5/14`

`15/8 = 2 - 1/8`

Ta có: `1/8 < 1/4 = 5/20 < 5/14`

`=> 1/8 < 5/14`

`=> 2 - 1/8 > 2-5/14`

`=> 23/14 < 15/8`

`13/8 > 12/8 = 3/2 > 8/9 = 1 - 1/9 > 1 - 1/6 = 5/6 > 2/6 = 1/3`

`=> 13/8 > 3/2 > 8/9 > 5/6 > 1/3`

`A = 2^4 . 2^3 . 3^3 = 2 . 2 . 2 . 2 . 2 . 2 . 2 . 3 . 3 . 3`

`B = 3^4 . 3^2 . 5^2 = 3.3.3.3.3.3.5.5`