Question

\(A=\dfrac{-7x^2}{\sqrt{x-3}-2}\)

tìm đkxđ

Answer 1

ĐKXĐ : \(\left\{{}\begin{matrix}x-3\ge0\\\sqrt{x-3}-2\ne0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x\ge3\\\sqrt{x-3}\ne2\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x\ge3\\x\ne7\end{matrix}\right.\)

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Answer 2

ĐKXĐ: \(\left\{{}\begin{matrix}x-3\ge0\\x-3\ne4\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\ge3\\x\ne7\end{matrix}\right.\)