Respuesta :

Answer:

[tex](4x + 12) \degree = 90 \degree \\ { \sf{ \{perpendicular \: angles \}}} \\ 4x + 12 = 90 \\ 4x = 90 - 12 \\ 4x = 78 \\ x = \frac{78}{4} \\ \\ { \underline{ \: \: x = 19.5 \: \: }}[/tex]