#### Answer

$y=20$

#### Work Step by Step

Using the properties of equality, the given equation, $
\sqrt{y+5}-4=1
$, is equivalent to
\begin{array}{l}
\sqrt{y+5}=1+4
\\\\
\sqrt{y+5}=5
.\end{array}
Raising both sides to the $\text{
2nd
}$ power, the solution to the equation above, $
\sqrt{y+5}=5
$, is
\begin{array}{l}
y+5=25
\\\\
y=25-5
\\\\
y=20
.\end{array}
Upon checking, $
y=20
$ satisfies the given equation.