Answer
$(0,3)$ is not a solution. $(-5,1)$ is a solution.
Work Step by Step
We are given: $x+2y \leq -3 $
Plug in $(0,3)$:
$0+2(3) \leq -3 $
$7 \leq -3 \rightarrow$ false
Plug in $(-5,1)$:
$-5+2(1) \leq -3 $
$-3 \leq -3 \rightarrow$ true
$(-5,1)$ is a solution