giúp mik vs ạaaaaaaaaaaaaaa

Đáp án:

`S= {13}`

Giải thích các bước giải:

`4/(x+1)-2/(x-2)=(x+3)/(x^2-x-2)` `(x \ne -1; x \ne 2)`

`<=> (4(x-2))/((x+1)(x-2))-(2(x+1))/((x+1)(x-2)) = (x+3)/(x^2-2x+x-2)`

`<=> (4(x-2))/((x+1)(x-2))-(2(x+1))/((x+1)(x-2)) = (x+3)/((x^2-2x)+(x-2))`

`<=> (4x-8)/((x+1)(x-2))-(2x+2)/((x+1)(x-2)) = (x+3)/(x(x-2)+(x-2))`

`<=> (4x-8-2x-2)/((x+1)(x-2)) = (x+3)/((x+1)(x-2))`

`=> 4x-8-2x-2= x+3`

`<=> 2x-10 = x+3`

`<=> 2x-x = 10+3`

`<=> x = 13` `(` Thỏa mãn `)`

Vậy `S= {13}`