Answer
The equivalent interval notation is $(-5, 3)$.
Work Step by Step
$-5$ $\lt$ $5 + 2x$ $\lt$ $11$
$-5 - 5$ $\lt$ $2x$ $\lt$ $11 - 5$
$- \frac{10}{2}$ $\lt$ $x$ $\lt$ $\frac{6}{2}$
$-5$ $\lt$ $x$ $\lt$ $3$
The equivalent interval notation is $(-5, 3)$.