Với `x >= 0,x \ne 1` có:
`B=[\sqrt{x}+3]/[\sqrt{x}+1]-3/[1-\sqrt{x}]+4/[x-1]`
`B=[(\sqrt{x}+3)(\sqrt{x}-1)+3(\sqrt{x}+1)+4]/[(\sqrt{x}-1)(\sqrt{x}+1)]`
`B=[x-\sqrt{x}+3\sqrt{x}-3+3\sqrt{x}+3+4]/[(\sqrt{x}-1)(\sqrt{x}+1)]`
`B=[x+5\sqrt{x}+4]/[(\sqrt{x}-1)(\sqrt{x}+1)]`
`B=[(\sqrt{x}+4)(\sqrt{x}+1)]/[(\sqrt{x}-1)(\sqrt{x}+1)]`
`B=[\sqrt{x}+4]/[\sqrt{x}-1]`
\(B=\dfrac{\sqrt{x}+3}{\sqrt{x}+1}-\dfrac{3}{1-\sqrt{x}}+\dfrac{4}{x-1}\)
\(B=\dfrac{\sqrt{x}+3}{\sqrt{x}+1}+\dfrac{3}{\sqrt{x}-1}+\dfrac{4}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\)
\(B=\dfrac{\left(\sqrt{x}+3\right)\left(\sqrt{x}-1\right)+3\left(\sqrt{x}+1\right)+4}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\)
\(B=\dfrac{x-\sqrt{x}+3\sqrt{x}-3+3\sqrt{x}+3+4}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\)
\(B=\dfrac{x+5\sqrt{x}+4}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\)
\(B=\dfrac{\left(\sqrt{x}+1\right)\left(\sqrt{x}+4\right)}{\left(\sqrt{x}+1\right)\left(\sqrt{x}-1\right)}\)
\(B=\dfrac{\sqrt{x}+4}{\sqrt{x}-1}\)
