ĐK: x\(\ge\)0,x\(\ne1\)
Để A có giá trị nguyên thì (\(\sqrt{x}-1\)) \(\in\)Ư(5)
\(\Rightarrow\sqrt{x}-1\:\in\){\(\pm1,\pm5\)}
Khi \(\sqrt{x}-1=\)1 \(\Leftrightarrow\sqrt{x}=2\Leftrightarrow x=4\:\left(TM\right)\)
Khi \(\sqrt{x}-1=\)-1 \(\Leftrightarrow\sqrt{x}=0\Leftrightarrow x=0\left(TM\right)\)
Khi \(\sqrt{x}-1=\)5 \(\Leftrightarrow\sqrt{x}=6\Leftrightarrow x=36\left(TM\right)\)
Khi \(\sqrt{x}-1=\)-5 \(\Leftrightarrow\sqrt{x}=-4\:\left(KTM\right)\)
Vậy x\(\in\){0;4;36} thì A có giá trị nguyên
