[tex] \\ 3(x + 1) + 2(x - 1) = 20 \\ \\ 3x + 3 + 2x - 2 = 20 \\ \\ 5x + 1 = 20 \\ \\ 5x = 20 - 1 \\ \\ 5x = 19 \\ \\ x = \frac{19}{5} \\ [/tex]