Question

Answer 1

\(B=\dfrac{5\sqrt{2}-2\sqrt{5}}{\sqrt{5}-\sqrt{2}}-\dfrac{9}{\sqrt{10}+1}\)

\(=\dfrac{\sqrt{10}\left(\sqrt{5}-\sqrt{2}\right)}{\sqrt{5}-\sqrt{2}}-\dfrac{9\left(\sqrt{10}-1\right)}{10-1}\)

\(=\sqrt{10}-\sqrt{10}+1=1\)

Answer 2

\(B=\dfrac{5\sqrt{2}-2\sqrt{5}}{\sqrt{5}-2}-\dfrac{9}{\sqrt{10}+1}\)

\(=\sqrt{10}-\sqrt{10}+1\)

=1