Answer
$-2\leq t\leq 4,\qquad$ or, $ t\in [-2,4]$
Work Step by Step
Use properties from the table 'Absolute Values and Intervals".
Apply Property 6:
$|x|\leq a\quad\Leftrightarrow\quad -a\leq x\leq a, \quad $ for a = positive number
we have
$-3\leq t-1\leq 3\qquad $ ... add 1 to all parts
$-2\leq t\leq 4$
This is a closed interval, $[-2,4]$
See table: "Types of intervals."