a) Ta có: \(\sqrt{x^3}-2\sqrt{x}-x\)
\(=x\sqrt{x}-2\sqrt{x}-\left(\sqrt{x}\right)^2\)
\(=\sqrt{x}\left(x-\sqrt{x}-2\right)\)
\(=\sqrt{x}\left(x-2\sqrt{x}+\sqrt{x}-2\right)\)
\(=\sqrt{x}\left[\sqrt{x}\left(\sqrt{x}-2\right)+\left(\sqrt{x}-2\right)\right]\)
\(=\sqrt{x}\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)\)
b) Ta có: \(-6x+5\sqrt{x}+1\)
\(=-6x+6\sqrt{x}-\sqrt{x}+1\)
\(=-6\sqrt{x}\left(\sqrt{x}-1\right)-\left(\sqrt{x}-1\right)\)
\(=\left(\sqrt{x}-1\right)\left(-6\sqrt{x}-1\right)\)
d) Ta có: \(7\sqrt{x}-6x-2\)
\(=-6x+3\sqrt{x}+4\sqrt{x}-2\)
\(=-3\sqrt{x}\left(2\sqrt{x}-1\right)+2\left(2\sqrt{x}-1\right)\)
\(=\left(2\sqrt{x}-1\right)\left(-3\sqrt{x}+2\right)\)
