Question

Phân tích thành nhân tử

Answer 1

= \(2^2-2.2.\left(\sqrt{5}\right)^2+\left(\sqrt{5}\right)^2\)

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

Answer 2

\(9-4\sqrt{5}=\left(\sqrt{5}-2\right)^2\)