a/ĐKXĐ:$x≥5$
$\sqrt{x-5}=5$
⇔$x-5=4$
⇔$x=9$ $(tmđk)$
b/ $\sqrt{x^2-6x+9}=5$
⇔$\sqrt{(x-3)^2}=5$
⇔$|x-3|=5$
⇔\(\left[ \begin{array}{l}x-3=5\\x-3=-5\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=8\\x=-2\end{array} \right.\)
c/ĐKXĐ:$x>-1$
$\sqrt{4x^2-4x+1}=x+1$
⇔$\sqrt{(2x-1)^2}=x+1$
⇔ $|2x-1|=x+1$
⇔ \(\left[ \begin{array}{l}2x-1=x+1\\2x-1=-x-1\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=2(tmđk)\\x=0(tmđk)\end{array} \right.\)
d/ $\sqrt{x^2-4x+4}=$$\sqrt{4x^2-12x+9}$
⇔ $\sqrt{(x-2)^2}=$$\sqrt{(2x-3)^2}$
⇔ $|x-2|=|2x-3|$
⇔\(\left[ \begin{array}{l}x-2=2x-3\\x-2=3-2x\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=1\\x=\dfrac{5}{3}\end{array} \right.\)
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