Question

tính giá trị biểu thức

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

Answer 1

=\(2\left|2-\sqrt{5}\right|\)

=\(2.\left(\sqrt{5}-2\right)\)

=\(2\sqrt{5}-4\)

Answer 2

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

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

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

\(=2\sqrt{5}-4\)