Answer
$\left\{x\ |\ -3\leq x\leq 3\right\}$ or $\left[-3,3\right]$
Work Step by Step
$-3\leq 3-2x\leq 9\qquad$ ... subtract $3$
$-6\leq-2x\leq 6\qquad$ ... divide with $-2$ (negative)
... the inequalities change direction ...
$3\geq x\geq-3$
Solution set: $\left\{x\ |\ -3\leq x\leq 3\right\}$ or $\left[-3,3\right]$
