39/$\left\{\begin{matrix}x+1\ge0\\9-x\ge0\\x^2+x-6\ne0\end{matrix}\right.$

$\Leftrightarrow \left\{\begin{matrix}x\ge-1\\x\le9\\x\ne2\\x\ne-3\end{matrix}\right.$

$\Leftrightarrow TXĐ: -1\le x\le9; x\ne2$

40/$\left\{\begin{matrix}10-x\ge0\\2|x|-1\ne0\\x+3>0\end{matrix}\right.$

$\Leftrightarrow \left\{\begin{matrix}x\le10\\x\ne\pm\dfrac{1}{2}\\x>-3\end{matrix}\right.$

$\Leftrightarrow TXĐ: -3<x\le10;x\ne\pm\dfrac{1}{2}$

41/$\left\{\begin{matrix}x^2+1\ge0\\x-2>0\\x-3\ne0\end{matrix}\right.$

$\Leftrightarrow \left\{\begin{matrix}x>2\\x\ne3\end{matrix}\right.$

$\Leftrightarrow TXĐ: x>2;x\ne3$

42/$\left\{\begin{matrix}-x\ge0\\|x+2|\ne0\end{matrix}\right.$

$\Leftrightarrow \left\{\begin{matrix}x\le0\\x\ne-2\end{matrix}\right.$

$\Leftrightarrow TXĐ: x\le0;x\ne-2$

43/$\left\{\begin{matrix}2x-1\ge0\\5-2x\ge0\\x^3+x\ne0\end{matrix}\right.$

$\Leftrightarrow \left\{\begin{matrix}x\ge\dfrac{1}{2}\\x\le\dfrac{5}{2}\\x\ne0\end{matrix}\right.$

$\Leftrightarrow TXĐ: \dfrac{1}{2}\le x\le\dfrac{5}{2}$

44/$\left\{\begin{matrix}2x-7\ge0\\3x+5\ge0\end{matrix}\right.$

$\Leftrightarrow \left\{\begin{matrix}x\ge\dfrac{7}{2}\\x\ge\dfrac{-5}{3}\end{matrix}\right.$

$\Leftrightarrow TXĐ: x\ge\dfrac{7}{2}$

45/$\left\{\begin{matrix}3x-1>0\\x^2-3x-4\ne0\end{matrix}\right.$

$\Leftrightarrow \left\{\begin{matrix}x>\dfrac{1}{3}\\x\ne-1\\x\ne4\end{matrix}\right.$

$\Leftrightarrow TXĐ: x>\dfrac{1}{3};x\ne4$

46/$\left\{\begin{matrix}-x\ge0\\x+3\ge0\\x-2\ge0\\\sqrt{x-2}-3\ne0\\x^2-x-2\ne0\end{matrix}\right.$

$\Leftrightarrow \left\{\begin{matrix}x\le0\\x\ge-3\\x\ge2\\x\ne11\\x\ne-1\\x\ne2\end{matrix}\right.$

$\Leftrightarrow TXĐ:∅$

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