Chapter 0 - Section 0.5 - Solving Polynomial Equations - Exercises - Page 30: 21

Solution set: $\{3, -1\}$

Multiply both sides with 2 (the common denominator) $x^{2}-2x-3=0$ We can factor the LHS: search for two factors of $-3$ whose sum is $-2$ ... $-3 $ and $+1$ $(x-3)(x+1)=0$ by the zero product principle, $x\in\{3, -1\}$