So,
[tex]9x + 4 = 3x + 16 \\ 9x = 3x + 16 - 4 \\ 9x = 3x + 12 \\9x - 3x = 12 \\ 6x = 12 \\ x = \frac{12}{6} \\ \\ x = 2[/tex]
Angle = 3x + 16
= 22
... Hope this will help...
