\(2-\sqrt{5}+2\sqrt{2}-\sqrt{10}=2\left(1+\sqrt{2}\right)-\sqrt{3}\left(1+\sqrt{2}\right)=\left(1+\sqrt{2}\right)\left(2-\sqrt{3}\right)\)\(x\sqrt{x}-x+\sqrt{x}-1=x\left(\sqrt{x}-1\right)+\left(\sqrt{x}-1\right)=\left(\sqrt{x}-1\right)\left(x+1\right)\)
a) \(2-\sqrt{5}+2\sqrt{2}-\sqrt{10}\)
\(=2.\left(1+\sqrt{2}\right)-\sqrt{5}\left(1+\sqrt{2}\right)\)
\(=\left(1+\sqrt{2}\right)\left(2-\sqrt{5}\right)\)
b) \(x\sqrt{x}-x+\sqrt{x}-1=x\left(\sqrt{x}-1\right)+\left(\sqrt{x}-1\right)\)
\(=\left(x-1\right)\left(\sqrt{x}+1\right)\)
ui mình lộn câu a là \(\sqrt{5}\) nha