Question

Answer 1

Lời giải:

a.

\(P=\left[\frac{\sqrt{a}}{\sqrt{a}(\sqrt{a}+2)}-\frac{1}{\sqrt{a}(\sqrt{a}+2)}\right]: \frac{\sqrt{a}-1}{(\sqrt{a}+2)^2}\)

\(=\frac{\sqrt{a}-1}{\sqrt{a}(\sqrt{a}+2)}.\frac{(\sqrt{a}+2)^2}{\sqrt{a}-1}=\frac{\sqrt{a}+2}{\sqrt{a}}\)

b.

\(P=\frac{\sqrt{a}+2}{\sqrt{a}}=1+\frac{2}{\sqrt{a}}> 1\) với mọi $a>0; a\neq 1$