Question

Giúp mình với,cần gấp !!!

Answer 1

a) \(C>0\) Khi:

\(\dfrac{-2}{\sqrt{x}-3}>0\)

\(\Leftrightarrow\sqrt{x}-3< 0\)

\(\Leftrightarrow\sqrt{x}< 3\)

\(\Leftrightarrow x< 9\)

Vậy: ..

b) \(C< 0\) khi:

\(\dfrac{-2}{\sqrt{x}-3}< 0\)

\(\Leftrightarrow\sqrt{x}-3>0\)

\(\Leftrightarrow\sqrt{x}>3\)

\(\Leftrightarrow x>9\)

Vậy: ...

Answer 2

`a, C > 0 <=> sqrt x - 3 < 0`.

`<=> sqrt x < 3`

`<=> x < 9`.

`b, C < 0 <=> sqrt x - 3 > 0`

`<=> sqrt x > 3`

`<=> x > 9`