Respuesta :

Annder

Step-by-step explanation:

Straight line = 180 °

5x + 78 = 180

5x = 180 - 78

5x = 102

x = 20.4

and y = 78 ° because y is an opposite angle of 78 °
y=78 degrees
5x + y = 180 degrees
Or, 5x+ 78 = 180 degrees
Or, 5x= 180-78
Or, 5x=102 degrees
Or, 5x=102/4
Therefore, x=20.4 degrees