`A=\sqrt{x^2-6x+9}+x-5`
`A=\sqrt{(x-3)^2}+x-5`
`A=|x-3|+x-5`
`A=3-x+x-5` `(x<3)`
`A=-2`
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`B=(\sqrt{x}+1)/(\sqrt{x}-2)+(2\sqrt{x})/(\sqrt{x}+2)-(5\sqrt{x}+2)/(x-4)` `(x>0,xne4)`
`B=((\sqrt{x}+1)(\sqrt{x}+2))/((\sqrt{x}-2)(\sqrt{x}+2))+(2\sqrt{x}(\sqrt{x}-2))/((\sqrt{x}+2)(\sqrt{x}-2))-(5\sqrt{x}+2)/(x-4)`
`B=(x+2\sqrt{x}+\sqrt{x}+2)/(x-4)+(2x-4\sqrt{x})/(x-4)-(5\sqrt{x}+2)/(x-4)`
`B=(x+2\sqrt{x}+\sqrt{x}+2+2x-4\sqrt{x}-5\sqrt{x}-2)/(x-4)`
`B=(3x-6\sqrt{x})/(x-4)`
`B=(3\sqrt{x}(\sqrt{x}-2))/((\sqrt{x}-2)(\sqrt{x}+2))`
`B=(3\sqrt{x})/(\sqrt{x}+2`
