[tex] \frac{x + 5}{3} - \frac{x + 15}{6} = \frac{1}{3} - \frac{x + 3}{4} \\ \\ 4(x + 5) - 2(x + 15) = 4 \times 1 - 3(x + 3) \\ \\ 4x + 20 - 2x - 30 = 4 - 3x - 9 \\ \\ 4x - 2x + 3x = 4 - 9 + 30 - 20 \\ \\ 5x = 5 \\ x = 1[/tex]
