`#tnvt`
`1/2\sqrt{4x+8}+\sqrt{36x+72}=16-\sqrt{x+2}(x>=-2)`
`<=>1/2 .\sqrt{4(x+2)}+\sqrt{36(x+2)}+\sqrt{x+2}=16`
`<=> 1/2 .2\sqrt{x+2}+6\sqrt{x+2}+\sqrt{x+2}=16`
`<=>\sqrt{x+2}+7\sqrt{x+2}=16`
`<=>8\sqrt{x+2]=16`
`<=>\sqrt{x+2}=2`
`<=>x+2=4`
`<=>x=2(tm)`
Vậy `S={2}`