Problem Solving (PS) | Re: If x - 7 = √x + √7 , x = ?

\(x-7=\sqrt{x}+\sqrt{7} \implies (\sqrt{x}+\sqrt{7})(\sqrt{x}-\sqrt{7}) = \sqrt{x}+\sqrt{7} \implies (\sqrt{x}+\sqrt{7})(\sqrt{x}-\sqrt{7} -1)=0 \)
thus \(\sqrt{x}+\sqrt{7}=0\) or \(\sqrt{x}-\sqrt{7} -1=0\)
thus \(\sqrt{x}=\sqrt{7} +1 \implies x= 8+2\sqrt{7}\)

Answer A

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