Answer
{$-1,-2,-3$}
Work Step by Step
Let us consider the first inequality.
$5-4x \geq 1 \implies 5-4(-1) \geq 1$ or, $9 \geq 1$
and $5-4(-2) \geq 1$ or, $13 \geq 1$
Now let us consider the second inequality.
$3-7x \lt 31 \implies 3-7(-1) \lt 31$ or, $10 \lt 31$
and $3-7(-2) \lt 31$ or, $17 \lt 31$
Also, $3-7(-3) \lt 31$ or, $24 \lt 31$
Our result is: {$-1,-2,-3$}