[tex]x + 4 = 48 - 2x \\ x + 2x = 48 - 4 \\ 3x = 44 \\ x = 44 \div 3 \\ x = 14 \frac{2}{3} [/tex]

[tex]8 - 4x = 2x - 16 \\ 2x + 4x = 8 + 16 \\ 6x = 24 \\ x = 24 \div 6 \\ x = 4[/tex]