thay x=25 vào biểu thức B ta có :

\(\dfrac{\sqrt{25}-3}{\sqrt{25}+2}\)=\(\dfrac{5-3}{5+2}\)=\(\dfrac{2}{7}\)

vậy tại x=25 thì B=\(\dfrac{2}{7}\)

chúc mừng mn 

(\(\dfrac{\sqrt{x}+1}{\sqrt{2x}+1}\)-\(\dfrac{\sqrt{2x}+\sqrt{x}}{\sqrt{2x}-1}\)-1):(1+\(\dfrac{\sqrt{x}+1}{\sqrt{2x}+1}\)_\(\dfrac{\sqrt{2x}+\sqrt{x}}{\sqrt{2x}-1}\))

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