Answer
$x=60$
Work Step by Step
The given equation is
$\Rightarrow 2\sqrt {x+4}=16$
Divide each side by $2$.
$\Rightarrow \frac{2\sqrt {x+4}}{2}=\frac{16}{2}$
Simplify.
$\Rightarrow \sqrt {x+4}=8$
Square each side of the equation.
$\Rightarrow (\sqrt{x+4})^2=8^2$
Simplify.
$\Rightarrow x+4=64$
Subtract $4$ from each side.
$\Rightarrow x+4-4=64-4$
Simplify.
$\Rightarrow x=60$
Check $x=60$.
$\Rightarrow 2\sqrt {x+4}=16$
$\Rightarrow 2\sqrt {60+4}=16$
$\Rightarrow 2\sqrt {64}=16$
$\Rightarrow 2\sqrt {8^2}=16$
$\Rightarrow 2(8)=16$
$\Rightarrow 16=16$
True.
Hence, the solution is $x=60$.
