a) Thay x = 9 vào B ta có
\(B=\dfrac{9+\sqrt{9}+1}{\sqrt{9}+2}=\dfrac{13}{5}\)
a: Thay x=9 vào B, ta được:
\(B=\dfrac{9+3+1}{3+2}=\dfrac{13}{5}\)
b: \(A=\dfrac{2x+4+x+\sqrt{x}-2-2x-2\sqrt{x}-2}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}\)
\(=\dfrac{x-\sqrt{x}}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}=\dfrac{\sqrt{x}}{x+\sqrt{x}+1}\)
d: \(P=A\cdot B=\dfrac{\sqrt{x}}{x+\sqrt{x}+1}\cdot\dfrac{x+\sqrt{x}+1}{\sqrt{x}+2}=\dfrac{\sqrt{x}}{\sqrt{x}+2}\)
Để P nguyên thì \(\sqrt{x}+2=2\)
hay x=0