Giúp mik nhé cảm ơn nhìu ạ

Đáp án + Giải thích các bước giải:

 `d)`

`4/(2\sqrt{3}-5)+4/(2\sqrt{3}+5)-(-9)/(13\sqrt{3})`

`= (4(2\sqrt{3}+5))/((2\sqrt{3}-5)(2\sqrt{3}+5)) +(4(2\sqrt{3}-5))/((2\sqrt{3}-5)(2\sqrt{3}+5))+(9\sqrt{3})/(13\sqrt{3}.\sqrt{3})`

`= (4(2\sqrt{3}+5)+4(2\sqrt{3}-5))/((2\sqrt{3}-5)(2\sqrt{3}+5)) +(9\sqrt{3})/(13.3)`

`= (8\sqrt{3}+20 + 8\sqrt{3}-20)/((2\sqrt{3})^2-5^2)+(3\sqrt{3})/13`

`= (16\sqrt{3})/(12 - 25) + (3\sqrt{3})/13`

`= (-16\sqrt{3})/13 + (3\sqrt{3})/13`

`= (-16\sqrt{3}+3\sqrt{3})/13`

`= (-13\sqrt{3})/13`

`= -\sqrt{3}`