a: A=5-4=1
b: \(B=3\sqrt{2}-10\sqrt{2}+8\sqrt{2}=\sqrt{2}\)
c: \(C=\left(\dfrac{1}{\sqrt{x}}-\dfrac{1}{\sqrt{x}+1}\right):\dfrac{\sqrt{x}-1}{\sqrt{x}}\)
\(=\dfrac{\sqrt{x}+1-\sqrt{x}}{\sqrt{x}\left(\sqrt{x}+1\right)}\cdot\dfrac{\sqrt{x}}{\sqrt{x}-1}=\dfrac{1}{x-1}\)
a.\(A=\sqrt{25}-\sqrt{16}=5-4=1\)
b.\(\sqrt{9.2}-2\sqrt{25.2}+2\sqrt{16.2}\)
\(=3\sqrt{2}-10\sqrt{2}+8\sqrt{2}=\sqrt{2}\)
c.\(C=\left(\dfrac{\sqrt{x}-1}{x-\sqrt{x}}-\dfrac{\sqrt{x}}{x+\sqrt{x}}\right):\left(1-\dfrac{1}{\sqrt{x}}\right)\)
\(C=\left(\dfrac{\sqrt{x}-1}{\sqrt{x}\left(\sqrt{x}-1\right)}-\dfrac{\sqrt{x}}{\sqrt{x}\left(\sqrt{x}+1\right)}\right):\left(1-\dfrac{1}{\sqrt{x}}\right)\)
\(C=\left(\dfrac{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)-\sqrt{x}\left(\sqrt{x}-1\right)}{\sqrt{x}\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\right):\left(\dfrac{\sqrt{x}-1}{\sqrt{x}}\right)\)
\(C=\left(\dfrac{x-1-x+\sqrt{x}}{\sqrt{x}\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\right).\dfrac{\sqrt{x}}{\sqrt{x}-1}\)
\(C=\dfrac{1}{x-1}\)
