Answer
$(-\infty,-2)$
Work Step by Step
Step 1. Rewrite the inequality as $\frac{1-x}{x+2}+1\lt0$ or $\frac{3}{x+2}\lt0$
Step 2. Identify the boundary point as $x=-2$
Step 3. Use test points at $x=-3, 0$, the signs of the left side are $-, +$
Step 4. The inequality requires negative (left region), thus the solution interval is $(-\infty,-2)$