TeX джерело:

\left\{ \begin{array}{l}{x^2} - 1 + 2(x + 1) - 6 = 3(x + 1),\\{x^2} - 1 \ne 0;\end{array} \right.\left\{ \begin{array}{l}{x^2} - 7 + 2x + 2 = 3x - 3,\\{x^2} \ne 1;\end{array} \right.\left\{ \begin{array}{l}x2 - x - 2 = 0,\\x \ne \pm 1;\end{array} \right.