Question

(căn bậc hai(x) + 1)^2 -3 = 0

Answer 1

\(\left(\sqrt{x}+1\right)^2-3=0\). (*)

ĐKXĐ: \(x\geq 0\).

(*) \(\Leftrightarrow\left(\sqrt{x}+1\right)^2=\left(\sqrt{3}\right)^2\)

\(\Leftrightarrow\sqrt{x}+1=\sqrt{3}\) 

\(\Leftrightarrow\sqrt{x}=\sqrt{3}-1>0\)

\(\Leftrightarrow x=4-2\sqrt{3}\) (TMĐK)

Answer 2

\(\left(\sqrt{x}+1\right)^2-3=0\left(x\ge0\right)\)

\(< =>\sqrt{x}+1=\sqrt{3}< =>\sqrt{x}=\sqrt{3}-1\)

\(< =>x=3-2\sqrt{3}+1\)