Question

x²+4x+5=2\(\sqrt{2x+3}\)

Answer 1

ĐKXĐ: 2x+3≥0 <=>x≥

⇔(2x+3-2 +1)+(x2+2x+1)=0

⇔( -1)2 +(x+1)2 =0

⇔ ⇔

⇔x=-1

Answer 2

ĐK:\(x\ge\frac{-3}{2}\)

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

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

\(\Rightarrow\left\{{}\begin{matrix}x=-1\\2x+3=1\end{matrix}\right.\)\(\Rightarrow x=-1\left(TM\right)\)

Vậy pt có tập nghiệm S={-1}