Chapter 2 - Linear and Quadratic Functions - Section 2.8 Equations and Inequalities Involving the Absolute Value Function - 2.8 Assess Your Understanding - Page 182: 36

$-4, 3, \frac{-1\pm 2i\sqrt {11}}{2}$.

Step 1. The original equation can be separated into two cases: $x^2+x=12$ or $x^2+x=-12$. Step 2. For $x^2+x=12$, we have $x^2+x-12=0 \longrightarrow (x+4)(x-3)=0 \longrightarrow x=-4, 3$. Step 3. For $x^2+x=-12$, we have $x^2+x+12=0 \longrightarrow x=\frac{-1\pm\sqrt {4-4(12)}}{2}=\frac{-1\pm 2i\sqrt {11}}{2}$.