`12,5xx6,4+19/5`

`=90+3,8`

`=93,8`

`180^0-90^0=90^0`

Để `A=(2n+3)/(n-2) in ZZ`

thì `2n+3 vdots n-2`

`=>2n-4+7 vdots n-2`

`=>2(n-2)+7 vdots n-2`

mà `2(n-2) vdots n-2`

`=>7 vdots n-2`

`=>n-2 in Ư(7)={+-1;+-7}`

`=>n in {3;1;9;-5}`

Vậy `n in {3;9;1;-5}` 

\(\left|\bigg(x+\dfrac{1}{2}\bigg)\bigg|2x-\dfrac{3}{4}\bigg|\right| =2x-\dfrac{3}{4}\)

\(\dfrac{2}{3}-\dfrac{5}{3}x=\dfrac{7}{10}x+\dfrac{5}{6}\\ \Leftrightarrow\dfrac{5}{3}x-\dfrac{7}{10}x=\dfrac{2}{3}-\dfrac{5}{6}\\ \Leftrightarrow\left(\dfrac{5}{3}-\dfrac{7}{10}\right)x=-\dfrac{1}{6}\\ \Leftrightarrow\dfrac{29}{30}x=-\dfrac{1}{6}\\ \Leftrightarrow x=-\dfrac{5}{29}\)