Question

tính

\(\left(\sqrt{5}-\sqrt{2}+1\right)\left(\sqrt{2}-1\right)\)

Answer 1

Lời giải:

\((\sqrt{5}-\sqrt{2}+1)(\sqrt{2}-1)=\sqrt{5}(\sqrt{2}-1)-(\sqrt{2}-1)^2\)

\(=\sqrt{10}-\sqrt{5}-(3-2\sqrt{2})=\sqrt{10}-\sqrt{5}-3+2\sqrt{2}\)

Answer 2

Ta có: \(\left(\sqrt{5}-\sqrt{2}+1\right)\left(\sqrt{2}-1\right)\)

\(=\left[\sqrt{5}-\left(\sqrt{2}-1\right)\right]\left(\sqrt{2}-1\right)\)

\(=\sqrt{10}-\sqrt{5}-3+2\sqrt{2}\)