\(b,\left(\dfrac{\sqrt{x}+1}{x-2\sqrt{x}}-\dfrac{1}{\sqrt{x}-2}\right).\left(x-3\sqrt{x}+2\right)\left(dkxd:x\ge0,x\ne4\right)\)
\(=\dfrac{\sqrt{x}+1-\sqrt{x}}{\sqrt{x}\left(\sqrt{x}-2\right)}.\left(x-3\sqrt{x}+2\right)\)
\(=\dfrac{x-\sqrt{x}-2\sqrt{x}+2}{\sqrt{x}\left(\sqrt{x}-2\right)}\)
\(=\dfrac{\sqrt{x}\left(\sqrt{x}-1\right)-2\left(\sqrt{x}-1\right)}{\sqrt{x}\left(\sqrt{x}-2\right)}\)
\(=\dfrac{\left(\sqrt{x}-1\right)\left(\sqrt{x}-2\right)}{\sqrt{x}\left(\sqrt{x}-2\right)}\)
\(=\dfrac{\sqrt{x}-1}{\sqrt{x}}\)
\(d,\dfrac{1}{5\sqrt{x}+7}+\dfrac{2}{3\sqrt{x}-2}-\dfrac{3}{15x+11\sqrt{x}-14}\left(dkxd:x\ge0,x\ne\dfrac{4}{9}\right)\)
\(=\dfrac{3\sqrt{x}-2+2\left(5\sqrt{x}+7\right)-3}{15x+11\sqrt{x}-14}\)
\(=\dfrac{3\sqrt{x}-2+10\sqrt{x}+14-3}{15x+11\sqrt{x}-14}\)
\(=\dfrac{13\sqrt{x}+9}{15x+11\sqrt{x}-14}\)
