#### Answer

$x=4$

#### Work Step by Step

Isolating the radical expression, the given expression is equivalent to
\begin{array}{l}\require{cancel}
6=\sqrt{x-3}+5
\\\\
6-5=\sqrt{x-3}
\\\\
1=\sqrt{x-3}
.\end{array}
Squaring both sides of the equation and then isolating the variable, the expression above is equivalent to
\begin{array}{l}\require{cancel}
1=\sqrt{x-3}
\\\\
(1)^2=(\sqrt{x-3})^2
\\\\
1=x-3
\\\\
1+3=x
\\\\
4=x
\\\\
x=4
.\end{array}