$\large{\color{red}{\textbf{Giải:}}}$

`(x + 3)/(x^2 - 9) + (2x - 1)/(x^2 - x - 6) = 5/(x^2 - 9)`

`<=>(x + 3)/(x^2 - 9) + (2x - 1)/(x^2 - x - 6) = 5/(x^2 - 9)`

`<=>(x + 3)/((x + 3)(x - 3)) + (2x - 1)/(x^2 - x - 6) = 5/((x + 3)(x - 3))`

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

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

`<=>(x + 2)(x + 3) + (2x - 1)(x + 3) = 5(x + 2)`

`<=>3x^2 + 10x + 3 = 5x + 10` `<=>3x^2 + 10x + 3 - 5x - 10 = 0`

`<=>3x^2 + 5x - 7 = 0`

`<=>x^2 + 5/3x - 7/3 = 0 `

`<=>x^2 + 5/3x = 7/3 `

`<=>x^2 + 5/3x +25/36= 7/3+25/36 `

`<=>(x + 5/6 )^2=109/36 `

`<=>x + 5/6 =sqrt{109/36 ` hoặc `x + 5/6 =-sqrt{109/36 `

`<=>x + 5/6 =sqrt109/6 ` hoặc `x + 5/6 =-sqrt109/6 `

`<=>x =(sqrt109-5)/6 ` hoặc `x =-(sqrt109-5)/6 `

`bb{Vậy::}` `x=(sqrt109-5)/6;x=-(sqrt109-5)/6`.