Đáp án:
\(\begin{array}{l}
a)DK:a \ge 0;b \ge 0;a \ne b\\
b)P = 1
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
a)DK:a \ge 0;b \ge 0;a \ne b\\
b)P = \left[ {\dfrac{{\left( {\sqrt a + \sqrt b } \right)\left( {a - \sqrt {ab} + b} \right)}}{{\sqrt a + \sqrt b }} - \sqrt {ab} } \right].{\left( {\dfrac{{\sqrt a + \sqrt b }}{{\left( {\sqrt a + \sqrt b } \right)\left( {\sqrt a - \sqrt b } \right)}}} \right)^2}\\
= \left( {a - 2\sqrt {ab} + b} \right).\dfrac{1}{{{{\left( {\sqrt a - \sqrt b } \right)}^2}}}\\
= {\left( {\sqrt a - \sqrt b } \right)^2}.\dfrac{1}{{{{\left( {\sqrt a - \sqrt b } \right)}^2}}} = 1\\
\to dpcm
\end{array}\)
