\(C=\dfrac{7\sqrt{x}-2}{2\sqrt{x}+1}\). Tìm x để C nguyên

Tìm \(x\in Z\) để \(B=\dfrac{x-2}{\sqrt{x}-3}\in Z\)

Tìm \(x\in Z\) để \(A=\dfrac{\sqrt{x}+3}{\sqrt{x}-3}\in Z-\)

\(A=\dfrac{3}{\sqrt{x}+3}\) \(\left(x\ge0;x\ne9\right)\)

Tìm GTLN của A

\(A=\dfrac{a+3}{2\left(\sqrt{a}+1\right)}\)

c/m \(A\ge1\)

\(A=\dfrac{x+3}{\sqrt{x}}\). Tìm x để \(A\sqrt{x}+x-1=2\sqrt{3x}+2\sqrt{x-2}\)