Question

Answer 1

4: ĐKXĐ: (2-x)(2+x)>=0

=>-2<=x<=2

5: ĐKXĐ: 2x-5>=0

hay x>=5/2

6: ĐKXĐ: \(\left\{{}\begin{matrix}2x-1>=0\\3-x>0\end{matrix}\right.\Leftrightarrow\dfrac{1}{2}< =x< =3\)

7: ĐKXĐ: \(\dfrac{x-1}{2x-6}>=0\)

=>x>3 hoặc x<=1

Answer 2

`8)`\(\dfrac{1}{\sqrt{x-2}-\sqrt{3}}\)

\(ĐK:x\ge2\)

       \(\sqrt{x-2}\ne\sqrt{3}\)

         \(\Leftrightarrow x-2\ne3\)

           \(\Leftrightarrow x\ne5\)

`9)`\(\dfrac{1}{\sqrt{x}}:\dfrac{\sqrt{x}-2}{\sqrt{x}+3}\)

\(ĐK:x\ge0\)

      \(x\ne0\)