a) \(x\sqrt{x}+4x+4\sqrt{x}\)
\(=\sqrt{x}\cdot\left(x+4\sqrt{x}+4\right)\)
b) \(\sqrt{6x}-x\cdot2\sqrt{3}\)
\(=\sqrt{6}\sqrt{x}-x\cdot2\sqrt{3}\)
\(=\sqrt{x}\left(\sqrt{6}-\sqrt{x}\cdot2\sqrt{3}\right)\)
\(=\sqrt{x}\left(\sqrt{6}-2\sqrt{3x}\right)\)