Answer
$x=50$
Work Step by Step
Using the properties of equality, the given equation, $
-\sqrt{2x}+4=-6
,$ is equivalent to
\begin{array}{l}\require{cancel}
-\sqrt{2x}=-6-4
\\\\
-\sqrt{2x}=-10
\\\\
\sqrt{2x}=10
.\end{array}
Squaring both sides of the equation above, then the solution/s is/are
\begin{array}{l}\require{cancel}
2x=100
\\\\
x=\dfrac{100}{2}
\\\\
x=50
.\end{array}
Upon checking, only $
x=50
$ satisfies the original equation.