- Lỗi xíu.

\(n\notin\left\{-5;-1;-4;-2\right\}\)

`1,5 xx x -25% = x`

`1,5 xx x - 1/4 - x =0`

`(1,5 - 1) xx x = 1/4`

`0,5 x =1/4`

`1/2 x =1/4`

`x = 1/4 : 1/2`

`x=1/2`

`1/2 x +3/5 (x-2)=3`

`1/2 x +3/5 x - 3/5 .2=3`

`(1/2 + 3/5) .x -6/5=3`

`11/10x = 3+6/5`

`11/10 x=21/5`

`x=21/5 :11/10`

`x=42/11`

- Mắt lagg nhìn ra sắt (iii). =(((((((