Answer
$x\gt-\dfrac{13}{4}$
Work Step by Step
Using the properties of inequalities, the solution to the given inequality, $
-3-x-3x\lt10
,$ is
\begin{array}{l}\require{cancel}
-x-3x\lt10+3
\\\\
-4x\lt13
\\\\
x\gt\dfrac{13}{-4}
\\\\
x\gt-\dfrac{13}{4}
.\end{array}