Question

Answer 1

a: \(x=\sqrt{5}+2-\sqrt{5}+2=4\)

Khi x=4 thì \(B=\dfrac{2-4}{2}=-1\)

b: \(A=\dfrac{2x-3\sqrt{x}+1+6\sqrt{x}+3-4\sqrt{x}-4}{4x-1}\)

\(=\dfrac{2x-\sqrt{x}}{4x-1}=\dfrac{\sqrt{x}}{2\sqrt{x}+1}\)

c: \(\Leftrightarrow3A^2-1=A-1\)

=>A(3A-1)=0

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\\dfrac{\sqrt{x}}{2\sqrt{x}+1}=\dfrac{1}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(nhận\right)\\x=1\left(nhận\right)\end{matrix}\right.\)