Question

help!!!

Answer 1

a) ĐKXĐ: \(x\ge0;y\ge0\)

\(\sqrt{5x}-\sqrt{3y}+\sqrt{3x}+\sqrt{5y}=\left(\sqrt{5x}+\sqrt{3x}\right)-\left(\sqrt{3y}+\sqrt{5y}\right)=\sqrt{x}\left(\sqrt{3}+\sqrt{5}\right)-\sqrt{y}\left(\sqrt{3}+\sqrt{5}\right)=\left(\sqrt{3}+\sqrt{5}\right)\left(\sqrt{x}-\sqrt{y}\right)\)

b)ĐKXĐ:\(x\ge0\)

\(x-\sqrt{x}-12=\left(x-4\sqrt{x}\right)+\left(3\sqrt{x}-12\right)=\sqrt{x}\left(\sqrt{x}-4\right)+3\left(\sqrt{x}-4\right)=\left(\sqrt{x}+3\right)\left(\sqrt{x}-4\right)\)