Question

Ac giúp em với, cảm ơn trước ạ

Answer 1

ĐKXĐ:
1.

\(\left\{{}\begin{matrix}x-1>0\\log_2\left(x-1\right)-1>0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x>1\\x-1>2\end{matrix}\right.\) \(\Leftrightarrow x>3\)

2.

\(\left\{{}\begin{matrix}x-1>0\\x-1\ne1\\\dfrac{x}{2-x^2}>0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x>1\\x\ne2\\\left[{}\begin{matrix}x< -\sqrt{2}\\0< x< \sqrt{2}\end{matrix}\right.\end{matrix}\right.\)

\(\Rightarrow1< x< \sqrt{2}\)